79,982 results on '"ELECTRON TRANSFER"'
Search Results
2. Efficient dry reforming of methane realized by photoinduced acceleration of oxygen migration rate.
- Author
-
Li, Zhende, Lu, Jianfeng, Ding, Jing, and Wang, Weilong
- Subjects
- *
X-ray photoelectron spectroscopy , *CARBON dioxide , *CATALYTIC activity , *PHOTOTHERMAL conversion , *TITANIUM dioxide - Abstract
[Display omitted] • Derived from Ti 3 C 2 T x , TiO 2 acts as a carrier, effectively avoiding agglomeration. • The generation rate of H 2 under light reaches 496 mmol g−1 h−1. • This provides a new idea for solar photothermal conversion. Methane dry reforming (DRM) can consume greenhouse gases (CH 4 and CO 2) to produce valuable Fischer-Tropsch syngas (CO and H 2). However, conventional thermally driven DRM consume large amounts of energy and face problems such as catalyst sintering and carbon deposition leading to insufficient catalytic activity. In this study, a photothermal synergistic TiO 2 /CeO 2 /Ru catalyst with high efficiency was designed. Under the light condition, the yields of H 2 and CO reached 496.3 mmol g−1 h−1 and 522.4 mmol g−1 h−1, respectively. In addition, the catalyst demonstrated excellent stability after 100 h cyclic stability test. In-situ X-ray photoelectron spectroscopy (IS-XPS) and density functional theory (DFT) calculations revealed that the heterojunction interface formed by TiO 2 /CeO 2 /Ru is favourable for capturing photogenerated electrons and suppressing the recombination rate of photons and holes, thus improving the photocatalytic performance. Furthermore, light-induced metal-to-metal charge transfer (MMCT) accelerated oxygen migration, which not only improved the catalytic activity, but also suppressed the formation of carbon deposits on the catalyst surface, thereby enhancing the cycling stability. This study explores the mechanism of photothermally synergistic DRM, which provides a new pathway for the efficient use of solar energy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Activating peroxymonosulfate with MOF-derived NiO-NiCo2O4/titanium membrane for water treatment: A non-radical dominated oxidation mechanism.
- Author
-
Zhang, Lijun, Ma, Huanran, Li, Yanda, Pan, Zonglin, Xu, Yuanlu, Wang, Guanlong, Fan, Xinfei, Zhao, Shuaifei, Lu, Huixia, and Song, Chengwen
- Subjects
- *
HOLLOW fibers , *CHARGE exchange , *CHARGE transfer , *WATER purification , *COMPLEX matrices - Abstract
[Display omitted] • A novel non-radical-dominated MOF-derived PMS catalytic membrane was proposed. • The MOF-derived heterojunction structure facilitated an enhanced electron transfer mechanism. • The formation of the heterostructure and the efficient cycling of Ni2+/Co3+ contributed to a remarkable non-radical process. • The M−NNCO−THFM demonstrated broad pH adaptability, excellent stability in complex water matrices, and good reusability. Traditional peroxymonosulfate (PMS) catalytic membranes dominated by radical pathways often face interference from complex components in water bodies. Herein, we employed a controlled electro-deposition technique to coat a Ni-Co metal–organic framework (MOF) precursor onto titanium hollow fiber membrane (THFM), followed by high-temperature calcination to synthesize a MOF-derived NiO-NiCo 2 O 4 /THFM (M−NNCO−THFM) PMS catalytic membrane. Then, the M−NNCO−THFM filtration integrated with PMS activation (MFPA process) for water treatment. Experimental results demonstrated that the M−NNCO−THFM MFPA process successfully achieved complete phenol (PE) removal via a non-radical-dominated degradation pathway, involving singlet oxygen (1O 2) and electron transfer, while exhibiting wide pH adaptability and exceptional stability in complex water matrices. Mechanism analysis revealed that the electron transfer process was significantly enhanced by the MOF-derived heterojunction structure, which increased the flat-band potential from 0.39 eV to 0.56 eV, thereby facilitating efficient electron transfer for PE removal. The non-radical 1O 2 pathway was primarily due to the cycling of metal valence states (Ni2+/Co3+), leading to the reduction of Co2+ and its reaction with PMS, resulting in the generation of reactive species. Furthermore, electrochemical measurements indicated that the M−NNCO−THFM exhibited lower charge transfer resistance and enhanced charge transfer efficiency compared to non-MOF-derived NNCO-THFM, corresponding to the superior catalytic performance and electrochemically active surface area of M−NNCO−THFM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. A Thermally Populated Germylene‐Based Donor‐Acceptor Diradical.
- Author
-
Zhao, Yu, Zhang, Yuchen, Wang, Tao, Pei, Runbo, Zhao, Yue, Xue, Xiao‐Song, and Wang, Xinping
- Abstract
This work reports synthesis of a germylene based donor‐acceptor molecule and its thermal excitation to a triplet state by coordination with a Lewis acid. Products have been characterized by single crystal X‐ray diffraction, EPR spectroscopy, and SQUID measurement, in conjunction with DFT calculation. The singlet‐triplet energy gap of the donor‐acceptor molecule is dramatically reduced from −18.8 to −7.2 kcal/mol by the coordination with B(C6F5)3 (BCF), which enables an intramolecular single electron transfer from one germylene moiety to another upon heating, forming an intramolecular radical ion pair with diradical character. The work provides an approach to the formation of thermally populated open‐shell species of heavier main group elements. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. The Effect of Dithionite and its Decomposition Products on Redox Mediators Used in the Cyclic Voltammetry of Nitrogenase Enzymes.
- Author
-
Bilyj, Jessica K., Gregg, Christina M., Wood, Craig C., and Rapson, Trevor D.
- Abstract
Cyclic voltammetry is a powerful tool to study enzyme mechanisms. Over the last decade, voltammetry has been applied to probe aspects of nitrogenase catalysis. One aspect that is often overlooked is the effect of dithionite (S2O42−, DTH) on nitrogenase and the mediators used during voltammetry experiments. Dithionite is routinely added to purification and storage buffers to protect nitrogenase and other anaerobic enzymes from oxygen. Dithionite has extremely complex chemistry with a myriad of decomposition products. Herein, we sought to systematically investigate the effect of dithionite and some of its decomposition products on the voltammetry of different redox mediators independently and in conjunction with nitrogenase. We found the major decomposition product sulfite (SO32−) gives rise to reductive catalysis. This cannot be distinguished from enzyme catalysis, particularly with cobaltocenium mediators which can result in amplified kobs values. We provide recommendations on how to identify and avoid interpreting 'pseudo' catalysis in lieu of enzyme catalysis by DTH and reinforce the requirement to remove DTH from the enzyme stock prior to performing cyclic voltammetry experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Nanohybrids of 2D Black Phosphorus with Phthalocyanines: Role of Interfacial Interactions in Heterostructure Development.
- Author
-
Scittarelli, Doriana, Coiai, Serena, Cicogna, Francesca, Legnaioli, Stefano, Dell'Angela, Martina, Verdini, Alberto, Costantini, Roberto, Serrano‐Ruiz, Manuel, Passaglia, Elisa, and Caporali, Maria
- Abstract
New 2D black phosphorus (bP)–phthalocyanine (Pc) nanohybrids have been synthesized by liquid phase exfoliation of black phosphorus crystals in the presence of two organic dyes: phthalocyanine (Pc) and manganese phthalocyanine (MnPc). The key role of the metal cation in the interfacial interaction between the organic dye and bP nanosheets was demonstrated by X‐ray absorption spectroscopy and associated with an electron transfer between the metal cation Mn2+ and bP nanosheets, which resembles a coordinative chemical bond. On the other hand, the interaction between bP nanosheets and pure phthalocyanine is governed by van der Waals forces. The fluorescence of both hybrids is significantly reduced indicating effective separation of the photoinduced charge, implying the formation of a heterojunction between the organic molecules and the bP nanosheets. These findings provide important insights into the interfacial interactions in bP‐Pc nanohybrids that are relevant for application in 2D organic/inorganic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. The Spin‐Selective Channels in Fully‐Exposed PtFe Clusters Enable Fast Cathodic Kinetics of Li‐O2 Battery.
- Author
-
Rao, Yuan, Yang, Jiawei, Tian, Jiaming, Ning, Wenjie, Guo, Shaohua, and Zhou, Haoshen
- Abstract
In Li‐O2 batteries (LOBs), the electron transfer between triplet O2 and singlet Li2O2 possesses a spin‐dependent character but is still neglected, while the spin‐conserved electron transfer without losing phase information should guarantee fast kinetics and reduced energy barriers. Here, we provide a paradigm of spin‐selective catalysis for LOB that the ferromagnetic quantum spin exchange interactions between Pt and Fe atoms in fully‐exposed PtFe clusters filter directional e‐spins for spin‐conserved electron transfer at Fe−Fe sites. The kinetics of O2/Li2O2 redox reaction is markedly accelerated as predicted by theoretical calculations, showing dramatically decreased relaxation time of the rate determining step for more than one order of magnitude, compared with the Fe clusters without spin‐selective behavior. In consequence, the assembled LOB provides ultrahigh energy conversion efficiency of 89.6 % at 100 mA g−1 under a discharge‐charge overpotential of only 0.32 V. This work provides new insights into the spin‐dependent mechanisms of O2/Li2O2 redox reaction, and the strategy of constructing spin catalysts at atomic level. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. EPR studies of ferredoxin in spinach and cyanobacterial thylakoids related to photosystem I-driven NADP+ reduction.
- Author
-
Utschig, Lisa M., Duckworth, Colin L., Niklas, Jens, and Poluektov, Oleg G.
- Abstract
Photosynthetic light-dependent reactions occur in thylakoid membranes where embedded proteins capture light energy and convert it to chemical energy in the form of ATP and NADPH for use in carbon fixation. One of these integral membrane proteins is Photosystem I (PSI). PSI catalyzes light-driven transmembrane electron transfer from plastocyanin (Pc) to oxidized ferredoxin (Fd). Electrons from reduced Fd are used by the enzyme ferredoxin-NADP
+ reductase (FNR) for the reduction of NADP+ to NADPH. Fd and Pc are both small soluble proteins whereas the larger FNR enzyme is associated with the membrane. To investigate electron shuttling between these diffusible and embedded proteins, thylakoid photoreduction of NADP+ was studied. As isolated, both spinach and cyanobacterial thylakoids generate NADPH upon illumination without extraneous addition of Fd. These findings indicate that isolated thylakoids either (i) retain a "pool" of Fd which diffuses between PSI and membrane bound FNR or (ii) that a fraction of PSI is associated with Fd, with the membrane environment facilitating PSI-Fd-FNR interactions which enable multiple turnovers of the complex with a single Fd. To explore the functional association of Fd with PSI in thylakoids, electron paramagnetic resonance (EPR) spectroscopic methodologies were developed to distinguish the signals for the reduced Fe-S clusters of PSI and Fd. Temperature-dependent EPR studies show that the EPR signals of the terminal [4Fe-4S] cluster of PSI can be distinguished from the [2Fe-2S] cluster of Fd at > 30 K. At 50 K, the cw X-band EPR spectra of cyanobacterial and spinach thylakoids reduced with dithionite exhibit EPR signals of a [2Fe-2S] cluster with g-values gx = 2.05, gy = 1.96, and gz = 1.89, confirming that Fd is present in thylakoid preparations capable of NADP+ photoreduction. Quantitation of the EPR signals of P700 + and dithionite reduced Fd reveal that Fd is present at a ratio of ~ 1 Fd per PSI monomer in both spinach and cyanobacterial thylakoids. Light-driven electron transfer from PSI to Fd in thylakoids confirms Fd is functionally associated (< 0.4 Fd/PSI) with the acceptor end of PSI in isolated cyanobacterial thylakoids. These EPR experiments provide a benchmark for future spectroscopic characterization of Fd interactions involved in multistep relay of electrons following PSI charge separation in the context of photosynthetic thylakoid microenvironments. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
9. Controlled electron transfer by molecular wires embedded in ultrathin insulating membranes for driving redox catalysis.
- Author
-
Frei, Heinz
- Abstract
Organic bilayers or amorphous silica films of a few nanometer thickness featuring embedded molecular wires offer opportunities for chemically separating while at the same time electronically connecting photo- or electrocatalytic components. Such ultrathin membranes enable the integration of components for which direct coupling is not sufficiently efficient or stable. Photoelectrocatalytic systems for the generation or utilization of renewable energy are among the most prominent ones for which ultrathin separation layers open up new approaches for component integration for improving efficiency. Recent advances in the assembly and spectroscopic, microscopic, and photoelectrochemical characterization have enabled the systematic optimization of the structure, energetics, and density of embedded molecular wires for maximum charge transfer efficiency. The progress enables interfacial designs for the nanoscale integration of the incompatible oxidation and reduction catalysis environments of artificial photosystems and of microbial (or biomolecular)-abiotic systems for renewable energy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Mn-porphyrins in a four-helix bundle participate in photo-induced electron transfer with a bacterial reaction center.
- Author
-
Williams, J. C., Faillace, M. S., Gonzalez, E. J., Dominguez, R. E., Knappenberger, K., Heredia, D. A., Moore, T. A., Moore, A. L., and Allen, J. P.
- Abstract
Hybrid complexes incorporating synthetic Mn-porphyrins into an artificial four-helix bundle domain of bacterial reaction centers created a system to investigate new electron transfer pathways. The reactions were initiated by illumination of the bacterial reaction centers, whose primary photochemistry involves electron transfer from the bacteriochlorophyll dimer through a series of electron acceptors to the quinone electron acceptors. Porphyrins with diphenyl, dimesityl, or fluorinated substituents were synthesized containing either Mn or Zn. Electrochemical measurements revealed potentials for Mn(III)/Mn(II) transitions that are ~ 0.4 V higher for the fluorinated Mn-porphyrins than the diphenyl and dimesityl Mn-porphyrins. The synthetic porphyrins were introduced into the proteins by binding to a four-helix bundle domain that was genetically fused to the reaction center. Light excitation of the bacteriochlorophyll dimer of the reaction center resulted in new derivative signals, in the 400 to 450 nm region of light-minus-dark spectra, that are consistent with oxidation of the fluorinated Mn(II) porphyrins and reduction of the diphenyl and dimesityl Mn(III) porphyrins. These features recovered in the dark and were not observed in the Zn(II) porphyrins. The amplitudes of the signals were dependent upon the oxidation/reduction midpoint potentials of the bacteriochlorophyll dimer. These results are interpreted as photo-induced charge-separation processes resulting in redox changes of the Mn-porphyrins, demonstrating the utility of the hybrid artificial reaction center system to establish design guidelines for novel electron transfer reactions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Mineralizing Biofilm towards Sustainable Conversion of Plastic Wastes to Hydrogen.
- Author
-
Li, Baoyuan, Xu, Zhijun, Wang, Ruifang, Nie, Rui, Tao, Zhengyu, and Huang, Xin
- Abstract
The integration of inorganic materials with biological machinery to convert plastics into fuels offers a promising strategy to alleviate environmental pollution and energy crisis. Herein, we develop a type of hybrid living material via biomineralization of CdS onto
Shewanella oneidensis ‐based biofilm, which is capable of sustainable hydrogen production from poly(lactic acid) (PLA) wastes under daylight. We reveal that the formed biofilm microstructure provides an independent anaerobic microenvironment that simultaneously supports cellular viability, maintains hydrogenase activity, and preserves the functional stability of CdS, giving rise to the efficient plastic‐to‐hydrogen conversion efficiency as high as 3751 μmol H2 g‐1 PLA. Besides, by genetically engineering transmembrane pili conduit and incorporating conductive nanomaterials to strengthen the electron transfer across cellular interface and biofilm matrices, we show that the conversion efficiency is further enhanced to 5862 μmol H2 g‐1 PLA. Significantly, we exhibit that a long‐term sustainable plastic‐to‐hydrogen conversion of 63 d could be achieved by periodically replenishing PLA wastes. Overall, by the synergistic integration of biotic‐abiotic characteristics the developed biofilm‐based biomineralized hybrid living material is anticipated to provide a new platform toward the efficient conversion of plastic wastes into valuable fuels, and bridge the gap between environmental contamination and green energy production. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
12. Regulating the Topologies and Photoresponsive Properties of Lanthanum‐Organic Frameworks.
- Author
-
Ren, Xin‐Ye, Chen, Fan‐Yao, Zhang, Chun‐Hua, Liang, Zhen‐Gang, Yu, Xiao‐Yue, Han, Song‐De, and Wang, Guo‐Ming
- Subjects
- *
CHARGE exchange , *RADICALS (Chemistry) , *RESEARCH personnel , *PHOTOCHROMISM , *LANTHANUM - Abstract
Metal‐organic frameworks (MOFs) show potential application in many domains, in which photochromic MOFs (PMOFs) have received enormous attention. Researchers mainly utilize photoactive ligands to build PMOFs. Recently, the mixed electron donating and accepting ligands strategies have also been used to construct PMOFs driven by the electron transfer between nonphotochromic moieties. However, the potential interligand competition inhibits the formation of PMOFs. Therefore, the exploration of single‐ligand‐guided assembly is conductive for building PMOFs. Considering the existing electron accepting and donating role of pyridyl and carboxyl, the pyridinecarboxyate derived from the fusion of pyridyl and carboxyl units may serve as single ligand to yield PMOFs (Figure 1d). In this work, the coordination assembly of bipyridinedicarboxylate (2,2′‐bipyridine‐4,4′‐dicarboxylic acid, H2bpdc; 1,10‐phenanthroline‐2,9‐dicarboxylic acid, H2pda) and LaCl3 generate two PMOFs, [La(bpdc)(H2O)Cl] (1) and [La(pda)(H2O)2Cl]⋅2H2O (2). Both complexes feature dinuclear lanthanum as building blocks with differences in the connecting number of likers, in which 1 has (4,8)‐connected topology and 2 exhibits sql topology. Their structural differences result in the diversities of photoresponsive functionalities. Compared with reported PMOFs built from photoactive ligands and mixed ligands, this study provides new available categories of single ligand for generating PMOFs and tuning the structure and photoresponsive properties via ligand substitution and external photostimulus. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Photoinduced Electron Transfer System from Cesium Lead Bromide Quantum Dots to Naphthalenediimide Supramolecular Polymers.
- Author
-
Manoj Lena, Amrutha, Yamauchi, Mitsuaki, Murakami, Hideyuki, Kubo, Naoki, Masuo, Sadahiro, Aratani, Naoki, and Yamada, Hiroko
- Abstract
Supramolecular polymers (SPs) formed via the stacking of π‐conjugated molecules are attractive nanomaterials because of their potential optoelectronic properties derived from the non‐covalent interaction between the π‐skeletons. Especially, SPs possessing naphthalenediimide (NDI) core units can act as superior electron acceptors due to their deep lowest unoccupied molecular orbital (LUMO). Interaction of such SP with electron donors can realize a charge transfer system, but this has not been established. Herein, we report a photoinduced electron transfer system from cesium lead bromide quantum dot (QD) as an electron donor to SP composed of cholesterol‐functionalized NDI derivatives. The supramolecular polymerization in a non‐polar solvent was analyzed in detail via microscopic and spectroscopic analyses. Upon mixing the SP with QDs, the photoluminescence intensity and lifetime of QDs decreased significantly, indicating efficient photoinduced electron transfer from QD to SP. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Intersystem Crossing, Photo‐Induced Charge Separation and Regioisomer‐Specific Excited State Dynamics in Fully Rigid Spiro Rhodammine‐Naphthalene/Anthraquinone Electron Donor‐Acceptor Dyads.
- Author
-
Ye, Kaiyue, Sukhanov, Andrey A., Li, Jiayu, Liu, Lishan, Chen, Xi, Zhao, Jianzhang, Voronkova, Violeta K., and Li, Ming De
- Subjects
- *
ELECTRON paramagnetic resonance , *ELECTRON spin , *RIGID dynamics , *CHARGE exchange , *CHARGE transfer , *ELECTRON donors - Abstract
We prepared a series fully rigid spiro electron donor‐acceptor orthogonal dyads, with closed form of rhodamine (Rho) as electron donor and naphthalene (Np)/anthraquinone (AQ) as electron acceptor, to access the long‐lived triplet charge separation (3CS) state, via the electron spin control method. We found strong dependency of the photophysical property of the dyads on the amino substitution positions of the Np chromophores in the dyads
1,8‐DaNp‐Rho and2,3‐DaNp‐Rho . Nanosecond transient absorption (ns‐TA) spectra show the population of the 3LE state (lifetime: 47 μs) for2,3‐DaNp‐Rho , however, long‐lived 3CS state was observed (τ CS=0.62 μs) forAQ‐Rho , with a CS quantum yield ofΦ CS=58 %. Based on femtosecond transient absorption (fs‐TA) spectra, spin orbit charge transfer ISC (SOCT‐ISC) is proposed to be responsible for the formation of the triplet states. Time‐resolved electron paramagnetic resonance (TREPR) spectra ofAQ‐Rho indicate the presence of two states, a 3LE state with zero field splitting (ZFS)D parameter of 1400 MHz andE parameter of −410 MHz, formed via radical pair ISC (RP‐ISC) and SOCT‐ISC mechanism; and a 3CS state with the electron spin‐spin interaction in the regime of spin‐correlated radical pair (SCRP). [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
15. Aeration‐Free Photo‐Fenton‐Like Reaction Mediated by Heterojunction Photocatalyst toward Efficient Degradation of Organic Pollutants.
- Author
-
Wang, Yan, Li, Lianxin, Zhou, Puyang, Gan, Yu, Liu, Weipeng, Wang, Yiwen, Deng, Yilin, Li, Hongping, Xie, Meng, and Xu, Yuanguo
- Abstract
The regulation of peroxymonosulfate (PMS) activation by photo‐assisted heterogeneous catalysis is under in‐depth investigation with potential as a replaceable advanced oxidation process in water purification, yet it remains a significant challenge. Herein, we demonstrate a strategy to construct polyethylene glycol (PEG) well‐coupled dual‐defect VO−M–Co3O4@CNx S‐scheme heterojunction to degrade organic pollutants without aeration, which dramatically provides abundant active sites, excellent photo‐thermal property, and distinct charge transport pathway for PMS activation. The degradation rate of VO−M−Co3O4@CNx in anaerobic conditions shows a higher efficient rate (4.58 min−1 g−2) than in aerobic conditions (1.67 min−1 g−2). Experimental evidence reveals that VO−M−Co3O4@CNx promotes more rapid redox conversion of photoexcited electrons induced by defects with PMS under anaerobic conditions compared to aerobic conditions. Additionally, in situ experiments and DFT provide mechanistic insights into the regulation pathway of PMS activation via synergistic defect‐induced electron, revealing the competitive effect between O2 and PMS over VO−M−Co3O4@CNx during the reaction process. The continuous flow reactor and flow cytometry results demonstrated that the VO−M−Co3O4@CNx/PMS/Vis system has remarkably enhanced stability and purification capability for removing organic pollutants. This work provides valuable insights into regulating the heterologous catalysis oxidation process without aeration through the photoexcitation synergistic PMS activation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Integration of Perylene Diimide into a Covalent Organic Framework for Photocatalytic Oxidation.
- Author
-
Li, Zhenping, Jiao, Junqiang, Fu, Wenlong, Gao, Ke, Peng, Xinyuan, Wang, Zhiwei, Zhuo, Huagui, Yang, Chao, Yang, Mingyu, Chang, Gang, Yang, Lei, Zheng, Xinglong, Yan, Yang, Chen, Feng, Zhang, Mingming, Meng, Zheng, and Shang, Xiaobo
- Subjects
- *
CONDUCTION bands , *PHOTOCATALYTIC oxidation , *ELECTRON transitions , *RADICAL anions , *DENSITY functional theory - Abstract
Perylene diimides (PDIs) have garnered considerable attention due to their immense potential in photocatalysis. However, manipulating the molecular packing within their aggregates and enhancing the efficiency of photogenerated carrier recombination remain significant challenges. In this study, we demonstrate the incorporation of a PDI unit into a covalent organic framework (COF), named PDI‐PDA, by linking an ortho‐substituted PDI with p‐phenylenediamine (PDA) to control its intermolecular aggregation. The incorporation enables precise modulation of electron‐transfer dynamics, leading to a ten‐fold increase in the efficiency of photocatalytic oxidation of thioether to sulfoxide with PDI‐PDA compared to the PDI molecular counterpart, with yields exceeding 90 %. Electron property studies and density functional theory calculations show that the PDI‐PDA with its well‐defined crystal structure, enhances π–π stacking and lowers the electron transition barrier. Moreover, the strong electron‐withdrawing ability of the PDI unit promotes the spatial separation of the valency band maximum and conduction band minimum of PDI‐PDA, suppressing the rapid recombination of photogenerated electron‐hole pairs and improving the charge‐separation efficiency to give high photocatalytic efficiency. This study provides a brief but effective way for improving the photocatalytic efficiency of commonly used PDI‐based dyes by integrating them into a framework skeleton. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Highly Sensitive Electrochemical Detection of Chlorpromazine Using Broccoli‐Like Copper–Aluminum‐Layered Double Hydroxide‐Modified Platinum Electrode.
- Author
-
Narayanan, Charuchitra Siva Sankara, Srinivasan, Soorya, LS, Sivagaama Sundari, Ezhilan, Madeshwari, Nesakumar, Noel, Gunasekaran, Balu Mahendran, and Hariharan, G.
- Subjects
- *
PLATINUM electrodes , *LAYERED double hydroxides , *CHLORPROMAZINE , *GROUNDWATER sampling , *ELECTROCHEMICAL sensors - Abstract
Chlorpromazine (CPZ), an antipsychotic drug derived from phenothiazine, can cause a range of adverse effects in humans, notably visual problems and hematological disorders upon consumption of chlorpromazine‐contaminated water. In this regard, a novel electrochemical sensing platform based on a copper–aluminum‐layered double hydroxide (Cu–Al LDH)‐modified platinum electrode for the highly sensitive and selective detection of chlorpromazine in groundwater samples has been developed. The immobilized Cu–Al LDH showed an electrocatalytic effect on chlorpromazine reduction and oxidation. Among the employed electroanalytical techniques, only the square‐wave voltammetry‐assisted Pt/Cu–Al LDH electrode could detect chlorpromazine with a remarkable sensitivity of 0.065 µA µM−1 over a broad linear detection range of 0.01–760 µM, with low detection and quantification limits of 4.86 and 16.18 nM, respectively. Furthermore, the developed electrode can rapidly detect chlorpromazine within less than 10 s. In addition, the diffusion profiles of steady‐state concentrations of oxidized and reduced chlorpromazine within the immobilized Cu–Al were studied using the Legendre wavelet method. Moreover, the developed Pt/Cu–Al LDH electrode demonstrated satisfactory rates in the quantification of chlorpromazine in groundwater samples, yielding satisfactory recovery rates (97.63–102.57%), confirming the practicability of the fabricated electrode in real‐time monitoring of chlorpromazine levels in groundwater without requiring any sample pretreatment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Tuning Electron‐Transfer Driving Force in Photosynthetic Special Pair Models.
- Author
-
Ramírez‐Wierzbicki, Ivana, Sanchez Merlinsky, Luciano, Pieslinger, German E., Domínguez, Sofía, Slep, Leonardo D., Baraldo, Luis M., and Cadranel, Alejandro
- Abstract
Visible‐light excitation of a family of bimetallic ruthenium polypyridines with the formula [RuII(tpy)(bpy)(‐CN)RuII(py)4L]n+ (
RuRuL n+), where L=Cl−, NCS−, DMAP and ACN, was used to prepare photoinduced mixed‐valence (PI‐MV) MLCT states as models of the photosynthetic reaction center. Ultrafast transient absorption spectroscopy allowed to monitor photoinduced IVCT bands between 6000 and 11000 cm−1. Mulliken spin densities resulting from DFT and (TD)DFT computations revealed the modulation of the charge density distribution depending on the ligand substitution pattern. Results are consistent with PI‐MV systems ranging from non‐degenerate Class II to degenerate Class III or II/III, with electronic couplings between 1000 and 3500 cm−1. These findings guide the control electron localization‐delocalization in charge‐transfer/charge‐separated excited states, like those involved in the photosynthetic reaction center. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
19. Sodium-Mediated Reductive anti -Dimagnesiation of Diarylacetyl-enes with Magnesium Bromide.
- Author
-
Yamaguchi, Haruka, Takahashi, Fumiya, Kurogi, Takashi, and Yorimitsu, Hideki
- Subjects
- *
SODIUM compounds , *ORGANOMAGNESIUM compounds , *SODIUM bromide , *GRIGNARD reagents , *CHARGE exchange - Abstract
Diarylacetylenes undergo anti -dimagnesiation using magnesium bromide and sodium dispersion to afford (E)-1,2-dimagnesioalkenes. This dimagnesiation utilizes simple magnesium bromide as a reduction-resistant electrophile, contrasting with the previously reported dimagnesiation using tricky organomagnesium halides. The resulting vicinal double Grignard reagents react with various electrophiles to yield multisubstituted alkenes stereoselectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Improving Photophysical Properties of Deazaflavin Derivatives by Acrylaldehyde Bridging: A Theoretical Investigation.
- Author
-
Guo, Huimin, Liu, Siyu, Liu, Xin, and Zhao, Jianzhang
- Subjects
- *
VIBRONIC coupling , *CHARGE exchange , *ACROLEIN , *ELECTRONIC structure , *PHOTOOXIDATION - Abstract
The electronic structure and photophysical properties of several acrylaldehyde‐bridged deazaflavin derivatives (cFLs) were investigated theoretically. The impact of acrylaldehyde bridging on photophysical properties of deazaflavin (cFL) is strongly site‐dependent. Specifically, the change of adiabatic energy of electronic transitions(ΔEad) and vibronic coupling promote fluorescent emission to be comparable to internal conversion of cFL and cFL4 (both C5−C6 and C9−N10 bridged, but C9−N10 bridged by propene), turning them eligible as fluorescent sensors. As El‐Sayed's rule is satisfied in cFL1(C5−C6 bridged), cFL2(C9−N10 bridged) and cFL3(both C5−C6 and C9−N10 bridged), intersystem crossing from first singlet excited state to triplet excited states (Tn) become dominant and the evolution of excited cFLs from T1 appears vital. The rate constants of photophysical processes indicate these cFLs are of dominantly high steady state T1 concentration and are potential triplet sensitizers. We expect the findings would pave the way for rational design of novel cFLs with extraordinary photophysical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Effect of the position of the substituent in the electrochemical reduction of nitro-substituted benzenesulfonyl chlorides.
- Author
-
Saley, Michael A., Hamed, Emad M., and Houmam, Abdelaziz
- Subjects
- *
RADICAL anions , *CHARGE exchange , *ELECTROLYTIC reduction , *SCISSION (Chemistry) , *CHLORIDES - Abstract
The electrochemical reduction of a series of nitro-substituted benzenesulfonyl chlorides is investigated. The results of the electrochemical study are analysed with the assistance of theoretical calculations. The study shows that the electron transfer mechanism depends on the position of the nitro substituent on the phenyl ring. The 3-nitrobenzenesulfonyl chloride follows a stepwise mechanism where the reduction leads to an intermediate radical anion. For the 4-nitrobenzenesulfonyl chloride, 2-nitrobenzenesulfonyl chloride, and 2,4-nitrobenzenesulfonyl chloride, the reduction follows a "sticky" dissociative mechanism, where the electron transfer and S–Cl bond cleavage are concerted. The dissociation products (arylsulfinyl radical and chloride anion) show strong interactions. The difference in behaviour is associated with the overlap of the π* orbital and the S–Cl σ* orbital for the latter three compounds. The through resonance stability of the arylsulfinyl radicals for the para and ortho nitro-substituted compounds facilitates the dissociation of the reduced structures. Upon reduction, the 3-nitrobenzenesulfonyl chloride and 4-nitrobenzenesulfonyl chloride, also produce the corresponding diaryl disulfones, which are easier to reduce that the parent molecules and hence induce an interesting autocatalytic mechanism. Such a mechanism, which depends on the concentration and the scan rate, does not take place with the 2-nitrobenzenesulfonyl chloride and 2,4-dinitrobenzenesulfonyl chloride due to the sterical hindrance of the nitro substituent at the ortho position, as it prevents the formation of the disulfones. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Insights into the function of metallic 1T phase tungsten disulfide as cocatalyst decorated zinc indium sulfide for enhanced photocatalytic hydrogen production activity.
- Author
-
Ding, Xiaoyan, You, Junhua, Xue, Yanjun, Wang, Jingjing, Qin, Yingying, Tian, Jian, Zhang, Hangzhou, and Wang, Xiaoxue
- Subjects
- *
HYDROGEN production , *ZINC sulfide , *INTERSTITIAL hydrogen generation , *ENERGY levels (Quantum mechanics) , *GIBBS' free energy , *TUNGSTEN trioxide , *INDIUM , *SILVER , *DISULFIDES - Abstract
We successfully decorated metallic 1T phase WS 2 (1T-WS 2) on the surface of ZnIn 2 S 4 and investigated the synergistic effect of 1T-WS 2 on ZnIn 2 S 4. Under simulated solar irradiation, the optimal hydrogen production rate of 1T-WS 2 /ZnIn 2 S 4 reaches 30.90 mmol/h g−1, which is 3.38 times higher than that of single ZnIn 2 S 4. [Display omitted] Improving the separation efficiency of carriers is an important part of enhancing photocatalytic activity. Herein, we successfully decorated metallic 1T phase tungsten disulfide (1T-WS 2) on the surface of zinc indium sulfide (ZnIn 2 S 4) and investigated the synergistic effect of 1T-WS 2 on ZnIn 2 S 4. The characterization results show that 1T-WS 2 improves the light absorption capacity and utilization efficiency, increases the catalytic active site, improves the photogenerated charge separation efficiency, and optimizes the reduction potential of ZnIn 2 S 4. Theoretical calculations show that compared with ZnIn 2 S 4 , 1T-WS 2 /ZnIn 2 S 4 has a smaller adsorption Gibbs free energy of the intermediate state H*, which is conducive to the catalytic reaction. Under simulated solar irradiation, the hydrogen (H 2) production rate of 1T-WS 2 /ZnIn 2 S 4 with a loading of 12 wt% reaches 30.90 mmol h−1 g−1, which is 3.38 times higher than that of single ZnIn 2 S 4 (9.13 mmol h−1 g−1). In addition, the apparent quantum efficiency of 1T-WS 2 /ZnIn 2 S 4 with a loading of 12 wt% reaches 21.14 % under monochromatic light at a wavelength of λ = 370 nm. This work analyzes the light absorption and carrier separation to the catalytic site, and elucidates the mechanism for the enhancement of the photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Roles of B[sbnd]O[sbnd]Cu sites and graphite nitrogen on persulfate non-radical activation for tetracycline degradation.
- Author
-
Zhao, Yue, Qiao, Lu, Zhang, Mingjuan, Xiao, Yao, Tao, Yani, Yang, Furong, Lin, Qian, and Zhang, Yi
- Subjects
- *
COPPER , *TETRACYCLINE , *TETRACYCLINES , *CHARGE exchange , *GRAPHITE , *NITROGEN - Abstract
[Display omitted] The activation of peroxymonosulfate (PMS) by carbon-based catalysts is deemed to be a promising method for the degradation of refractory organic contaminants in wastewater. Herein, a Cu-doping strategy in B and N co-doped carbon nanotubes with highly dispersed B O Cu sites and graphite nitrogen were successfully synthesized for activating PMS to degradate tetracycline. The best removal rate of tetracycline within 60 min (97.63 %) was obtained by the 1.5 % Cu-BNC and the degradation rate was increased by 17.9 times. The enhanced catalyst activity was attributed to the promoting the cycle of the Cu(I)/Cu(II) redox pair by the formed B O Cu sites, and the accelerating the electron transfer process by the adsorption of graphitic N for PMS. The non-free radical pathway including 1O 2 and electron transfer played a dominant role in the 1.5 % Cu-BNC/PMS system. The degradation intermediates of TC were identified and three possible degradation pathways were proposed. Further toxicity analysis of the intermediates showed that the 1.5 % Cu-BNC/PMS system had a significant effect on weakening and reducing the biological toxicity and mutagenicity of TC. Moreover, it presented an excellent degradation performance in raw natural water. In general, the proposed regulation of carbon-based catalysts via the coordination-driven effect provides ideas for efficient wastewater treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Tethered heme domains in a triheme cytochrome allow for increased electron transport distances.
- Author
-
Nash, Benjamin W., Fernandes, Tomás M., Burton, Joshua A. J., Morgado, Leonor, van Wonderen, Jessica H., Svistunenko, Dimitri A., Edwards, Marcus J., Salgueiro, Carlos A., Butt, Julea N., and Clarke, Thomas A.
- Abstract
Decades of research describe myriad redox enzymes that contain cofactors arranged in tightly packed chains facilitating rapid and controlled intra‐protein electron transfer. Many such enzymes participate in extracellular electron transfer (EET), a process which allows microorganisms to conserve energy in anoxic environments by exploiting mineral oxides and other extracellular substrates as terminal electron acceptors. In this work, we describe the properties of the triheme cytochrome PgcA from Geobacter sulfurreducens. PgcA has been shown to play an important role in EET but is unusual in containing three CXXCH heme binding motifs that are separated by repeated (PT)x motifs, suggested to enhance binding to mineral surfaces. Using a combination of structural, electrochemical, and biophysical techniques, we experimentally demonstrate that PgcA adopts numerous conformations stretching as far as 180 Å between the ends of domains I and III, without a tightly packed cofactor chain. Furthermore, we demonstrate a distinct role for its domain III as a mineral reductase that is recharged by domains I and II. These findings show PgcA to be the first of a new class of electron transfer proteins, with redox centers separated by some nanometers but tethered together by flexible linkers, facilitating electron transfer through a tethered diffusion mechanism rather than a fixed, closely packed electron transfer chain. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Effect of Halide Ions on the TiO2-mediated Photocatalysis of Carbendazim in Aqueous Medium Under Near-ultraviolet Light Irradiation.
- Author
-
Bragetta, Margherita, Germani, Raimondo, Tiecco, Matteo, Alabed, Husam B. R., and Del Giacco, Tiziana
- Subjects
CARBENDAZIM ,CHARGE exchange ,TITANIUM dioxide ,PHOTOCATALYSIS ,BROMIDES ,PHOTODEGRADATION ,IRRADIATION - Abstract
The degradation of carbendazim (CBZ) through TiO
2 photocatalysis, in the presence of halide ions and under near-UV light irradiation, was investigated. HPLC–MS technique was used to characterize the photoproducts. Spectrophotometric analysis showed that CBZ degraded slowly in TiO2 aqueous dispersions containing no salt (CBZ conversion of 6% after ca. 5 h of irradiation). The photodegradation efficiency increased particularly by addition of bromide salts. Indeed, CBZ reached complete degradation after ca. 30 min at the maximum concentration of NaBr used (0.05 M). Two significant aspects have emerged from the data analysis: the bromide role is to cause inhibition of the electron–hole recombination, a reaction known to be competitive with the reactive process; CBZ photodegradation is especially initiated by direct hole transfer pathway, whereas the OH• role is crucial in the catalyst regeneration process. Degradation attempts under sunlight appeared promising for a more sustainable photocatalytic process. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
26. Copper Nanoclusters Imparted Metalloporphyrin Based Metal‐Organic Frameworks for Enhanced CO2 Electroreduction.
- Author
-
Wang, Qian, Feng, Bangli, Rong, Yan, Pan, Danxuan, Ye, Mingfu, Xin, Zhifeng, and Chen, Yifa
- Subjects
- *
COPPER , *CHARGE exchange , *CHARGE transfer , *METAL-organic frameworks , *ENERGY consumption - Abstract
Strategies that can introduce catalytic auxiliary into electrocatalysts to boost the performance of electrocatalytic CO2 reduction reaction (CO2RR) are meaningful in exploring hybrid electrocatalytic systems. Here, a series of hybrid electrocatalysts (Cu NCs@MOF‐545‐M, M=Fe, Co and Ni) have been prepared by assembly Cu NCs with MOF‐545‐M (M=Fe, Co and Ni) and successfully applied in electrocatalytic CO2RR. In the obtained MOF‐545‐M (M=Fe, Co and Ni), the integration of Cu NCs with MOF‐545‐M (M=Fe, Co and Ni) can create a hybrid electrocatalytic system that enhances the charge transfer efficiency and electrocatalytic CO2RR activity. Specifically, the optimal Cu NCs@MOF‐545‐Co presents remarkable FECO over a wide potential range (−0.7 V to −1.0 V), high CO generation rate (8.2 mol m−2 h−1) and excellent maximum energy efficiency (69 %, −0.7 V), which is superior to Cu NCs and MOF‐545‐Co, and represented to be one of the best performances to date. This work demonstrates a facile approach to significantly improve the FECO by loading metal nanoclusters into MOFs, providing a valuable reference for future studies on hybridization strategies to enhance the performance of electrocatalysts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Enhancement of the anaerobic biodegradation efficiency of azo dye by anthraquinone-loaded biochar biofilm: factors affecting biofilm formation and the enhancement mechanism.
- Author
-
Wang, Guangyuan, Cui, Chenhao, Wang, Yuqian, Pang, Jiwei, Yang, Shanshan, Wu, Chuandong, Fang, Rui, Zhang, Luyan, Ren, Nanqi, and Ding, Jie
- Subjects
- *
CARBON-based materials , *MICROBIAL communities , *WASTEWATER treatment , *CHARGE exchange , *MICROBIAL diversity , *BIOFILMS - Abstract
Carbon-based materials that serve as microbial carriers, and the role of surface-formed biofilms in anaerobic digestion, merit further investigation. This study explored the role and mechanism behind the biodegradation enhancement of biofilms formed onto anthraquinone-loaded biochar (AQS-BC) surfaces through the anaerobic decolorization process of azo dye Reactive Red 2, and optimized the conditions for AQS-BC biofilm formation. The results indicated that the AQS-BC biofilm system exhibited high treatment efficiency and stability in RR2 anaerobic decolorization. RR2 led to the accumulation of volatile fatty acids (VFAs) and inhibition of methane production, while the presence of AQS increased methane production. The effects of sludge concentration, contact time, carbon source concentration, and RR2 concentration on biofilm maturity were also analyzed. Combining biochemical characteristics, electrochemical properties, surface structure, and microbial community analysis, a mechanism for the anaerobic decolorization of RR2 via AQS-BC as a microbial carrier was proposed. This study provides insights into the roles of biofilms in the anaerobic wastewater treatment processes. Article Highlights: AQS-BC biofilm system exhibited superiority and stability in long-term anaerobic biodecolorization of RR2. AQS-BC biofilm effectively promoted the production of VFAs and alleviated the inhibitory of RR2 on methanogenesis. AQS-BC biofilm had a higher EPS content, denser structure, and higher microbial diversity compared to BC biofilm. Four inoculation conditions affecting biofilm formation were elucidated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Late‐Stage Functionalization Using a Popular Titrating Agent: Aryl‐Chlorides and ‐Fluorides Activation by the Diphenylacetic Acid Dianion.
- Author
-
Cerveri, Alessandro, Russo, Giulia, Sparascio, Sara, Merli, Daniele, Maggi, Raimondo, Della Ca', Nicola, Lanzi, Matteo, and Maestri, Giovanni
- Abstract
Aryl‐chlorides and ‐fluorides are common building blocks, but their use in synthesis is limited by the high stability of their Ar−X bonds. The generation of aryl radicals
via activation of strong Ar−X bonds is possible through the irradiation of tailor‐made organic anions, which become reductants stronger than lithium metal. We report that the combination of visible light with the cheap diphenylacetic acid dianion is an even better tool, showing excellent activity across a variety of complex substrates and providing opportunities for late‐stage drug modification. Ar−X bonds are chemoselectively activated in the presence of more easily reducible functions, such as Alk‐Cl ones and carbonyl groups. These results pave the way to original synthetic strategies that would be otherwise considered impossible. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
29. Regulatory Mechanisms and Applications of Rare Earth Elements‐Based Electrocatalysts†.
- Author
-
Gao, Qinlong, Wang, Haoyuan, Liu, Chunxiao, Luo, Laihao, Li, Xu, jiang, Qiu, Ji, Yuan, Zheng, Tingting, and Xia, Chuan
- Subjects
- *
RARE earth metals , *OXYGEN evolution reactions , *HYDROGEN transfer reactions , *OXIDATION-reduction reaction , *OXYGEN reduction - Abstract
Comprehensive Summary Key Scientists Amidst the pressing environmental challenges posed by the prevalent reliance on fossil fuels, it becomes imperative to seek sustainable alternatives and prioritize energy efficiency. Electrocatalysis, which is renowned for its high efficiency and environmental friendliness, has garnered significant attention. Rare earth elements (REEs), distinguished by their unique electronic and orbital structures, play a crucial role in electrocatalysis. The strategic integration of REEs into catalysts allows for the fine‐tuning of atomic structures, which in turn, significantly boosts catalytic performance. Despite substantial advancements in rare earth‐based materials for electrocatalysis, a comprehensive overview of the regulatory mechanisms involving REEs is lacking. In this mini‐review, we systematically explore the regulatory mechanisms of REEs within electrocatalysts and their pivotal roles in essential electrocatalytic processes such as the CO2 reduction reaction, oxygen reduction reaction, and hydrogen evolution reaction. We commence with an elucidation of REEs, proceed to delineate their regulatory impacts on electrocatalysts and delve into their applications in key electroreduction reactions. We conclude with discussions on current limitations and prospects for further advancements in this burgeoning field of research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. The Photodynamic Agent Designed by Involvement of Hydrogen Atom Transfer for Enhancing Photodynamic Therapy.
- Author
-
Fan, Zhuo, Teng, Kun‐Xu, Xu, Yuan‐Yuan, Niu, Li‐Ya, and Yang, Qing‐Zheng
- Abstract
Although Type‐I photodynamic therapy has attracted increasingly growing interest due to its reduced dependence on oxygen, the design of effective Type‐I photosensitizers remains a challenge. In this work, we report a design strategy for Type‐I photosensitizers by the involvement of hydrogen atom transfer (HAT). As a proof of concept, a HAT‐involved Type‐I PS, which simultaneously generates superoxide and carbon‐centered radicals under light‐irradiation, was synthesized. This photosensitizer is comprised of a fluorene‐substituted BODIPY unit as an electron acceptor covalently linked with a triphenylamine moiety as an electron donor. Under light‐irradiation, photo‐induced intramolecular electron transfer occurs to generate the BODIPY anion radical and triphenylamine cation radical. The former transfers electrons to oxygen to generate O2−⋅, while the latter loses a proton to produce a benzyl carbon‐centered radical which is well characterized. The resulting carbon‐centered radicals efficiently oxidize NADH by HAT reaction. This photosensitizer demonstrates remarkable photocytotoxicity even under hypoxic conditions, along with outstanding in vivo antitumor efficacy in mouse models bearing HeLa tumors. This work offers a novel strategy for the design of Type‐I photosensitizers by involvement of HAT. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Advancements in Graphite Anodes for Lithium‐Ion and Sodium‐Ion Batteries: A Review.
- Author
-
Xiong, Kai, Qi, Tianshuang, and Zhang, Xiong
- Subjects
- *
CHARGE exchange , *ENERGY storage , *ENERGY consumption , *GRAPHITE , *RENEWABLE energy sources - Abstract
Amidst the escalating global energy demand and the rapid advancement of renewable energy technologies, battery technology plays an indispensable role in energy storage. As a crucial anode material, Graphite enhances performance with significant economic and environmental benefits. This review provides an overview of recent advancements in the modification techniques for graphite materials utilized in lithium‐ion and sodium‐ion batteries. This review initially presents various modification approaches for graphite materials in lithium‐ion batteries, such as electrolyte modification, interfacial engineering, purification and morphological modification, composite modification, surface modification, and structural modification, while also addressing the applications and challenges of graphite anode materials in this context. Subsequently, it focuses on the modification methods for graphite anode materials in sodium‐ion batteries, including composite material modification, electrolyte optimization, surface modification, and structural modification, along with their respective applications and challenges. It then compares the modification strategies across different battery systems and proposes innovative modification methods and alternative materials for future graphite anode materials to further enhance their performance in batteries. Finally, the review concludes with a summary of the significance of researching graphite anode material modifications and offers perspectives on future developments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Exploring the Impact of Water Content in Solvent Systems on Photochemical CO 2 Reduction Catalyzed by Ruthenium Complexes.
- Author
-
Kuramochi, Yusuke, Kamiya, Masaya, and Ishida, Hitoshi
- Subjects
- *
CATALYTIC activity , *ARTIFICIAL photosynthesis , *RUTHENIUM compounds , *ELECTRON sources , *CHARGE exchange , *RUTHENIUM catalysts - Abstract
To achieve artificial photosynthesis, it is crucial to develop a catalytic system for CO2 reduction using water as the electron source. However, photochemical CO2 reduction by homogeneous molecular catalysts has predominantly been conducted in organic solvents. This study investigates the impact of water content on catalytic activity in photochemical CO2 reduction in N,N-dimethylacetamide (DMA), using [Ru(bpy)3]2+ (bpy: 2,2′-bipyridine) as a photosensitizer, 1-benzyl-1,4-dihydronicotinamide (BNAH) as an electron donor, and two ruthenium diimine carbonyl complexes, [Ru(bpy)2(CO)2]2+ and trans(Cl)-[Ru(Ac-5Bpy-NHMe)(CO)2Cl2] (5Bpy: 5′-amino-2,2′-bipyridine-5-carboxylic acid), as catalysts. Increasing water content significantly decreased CO and formic acid production. The similar rates of decrease for both catalysts suggest that water primarily affects the formation efficiency of free one-electron-reduced [Ru(bpy)3]2+, rather than the intrinsic catalytic activity. The reduction in cage-escape efficiency with higher water content underscores the challenges in replacing organic solvents with water in photochemical CO2 reduction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Pt-N catalytic centres concisely enhance interfacial charge transfer in amines functionalized Pt@MOFs for selective conversion of CO2 to CH4.
- Author
-
Zahid, Muhammad, Ismail, Ahmed, Ullah, Rizwan, Ali, Usman, Raziq, Fazal, Alrebdi, Tahani A., Alodhayb, Abdullah N., Ali, Sharafat, and Qiao, Liang
- Subjects
- *
CHARGE transfer , *POLYOLS , *METAL-organic frameworks , *METAL catalysts , *METHANE , *CARBON dioxide - Abstract
[Display omitted] Improving ligand-to-active metal charge transfer (LAMCT) by finely tuning the organic ligand is a decisive strategy to enhance charge transfer in metal organic frameworks (MOFs)-based catalysts. However, in most MOFs loaded with active metal catalysts, electron transmission encounters massive obstacle at the interface between the two constituents owing to poor LAMCT. Herein, amines (–NH 2) functionalized MOFs (NH 2 -MIL-101(Cr)) encapsulated active metal Pt nanoclusters (NCs) catalysts are synthesized by the polyol reduction method and utilized for the photoreduction of CO 2. Surprisingly, the introduction of –NH 2 (electron donating) groups within the matrix of MIL-101(Cr) improved the electron migration through the LAMCT process, fostering a synergistic interaction with Pt. The combined experimental analysis exposed the high number of metallic Pt (Pt0) in Pt@NH 2 -MIL-101(Cr) catalyst through seamless electron shuttling from N of –NH 2 group to excited Pt generating versatile hybrid Pt-N catalytic centres. Consequently, these versatile hybrid catalytic centres act as electro-nucleophilic centres, which enable the efficient and selective conversion of C O bond in CO 2 to harvest CH 4 (131.0 µmol.g−1) and maintain excellent stability and selectivity for consecutive five rounds, superior to Pt@MIL-101(Cr) and most reported catalysts. Our study verified that the precise tuning of organic ligands in MOFs immensely improves the surface-active centres, electron migration, and catalytic selectivity of the excited Pt NCs catalysts encaged inside MOFs through an improved LAMCT pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Recent progress in the characterization and application of exo-electrogenic microorganisms.
- Author
-
Jayathilake, Chamindu, Piyumika, Gayani, Nazeer, Zumaira, Wijayawardene, Nalin, Rajakaruna, Shalini, Kumla, Jaturong, and Fernando, Eustace
- Abstract
Exo-electrogenic microorganisms are characterized by their special metabolic capability of transferring metabolic electrons out of their cell, into insoluble external electron acceptors such as iron or manganese oxides and electrodes, or vice versa take up electron from electrodes. Their conventional application is primarily limited to microbial fuel cells for electrical power generation and microbial electrolysis cells for the production of value-added products such as biohydrogen, biomethane and hydrogen peroxide. The utility of exo-electrogenic organisms has expanded into many other applications in recent times. Such examples include microbial desalination cells, microbial electro-synthesis cells producing value-added chemicals such as bio-butanol and their applications in other carbon sequestration technologies. Additionally, electrochemically-active organisms are now beginning to be employed in biosensor applications for environmental monitoring. Additionally, the utility of biocathodes in bio-electrochemical systems is also a novel application in catalyzing the cathodic oxygen reduction reaction to enhance their electrochemical performance. Advances have also been made in the expansion and use of other organisms such as the usage of photosynthetic microorganisms for the fabrication of self-sustained bio-electrochemical systems. This review attempts to provide a comprehensive picture of the state-of the art of exo-electrogenic organisms and their novel utility in bioelectrochemical systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Directional Electron Transfer in Enzymatic Nano‐Bio Hybrids for Selective Photobiocatalytic Conversion of Nitrate.
- Author
-
Bian, Jiyong, An, Xiaoqiang, Zhao, Jing, Liao, Yang, Lan, Xianen, Liu, Ruiping, Hu, Chengzhi, Chen, Jie‐jie, Liu, Huijuan, and Qu, Jiuhui
- Subjects
- *
SUSTAINABILITY , *CHARGE exchange , *NITRITE reductase , *DENITRIFICATION , *NITRIDES , *NITRATE reductase - Abstract
Semi‐artificial photosynthetic system (SAPS) that combines enzymes or cellular organisms with light‐absorbing semiconductors, has emerged as an attractive approach for nitrogen conversion, yet faces the challenge of reaction pathway regulation. Herein, we find that photoelectrons can transfer from the −C≡N groups at the edge of cyano‐rich carbon nitride (g‐C3N4‐CN) to nitrate reductase (NarGH), while the direct electron transfer to nitrite reductase (
cd 1NiR) is inhibited due to the physiological distance limit of active sites (>14 Å). By means of the directional electron transfer between g‐C3N4‐CN and extracted biological enzymes, the product of the denitrification reaction was switched from inert N2 to usable nitrite with an unprecedented selectivity of up to 95.3 %. The converted nitrite could be further utilized by anammox microbiota and dissimilatory nitrate reduction to ammonia (DNRA) microorganisms, doubling the efficiency of total nitrogen removal (96.5±2.3 %) for biological nitrogen removal and ammonia generation (12.6 mg NH4+‐N L−1 h−1), respectively. Thus, our work paves an appealing way for the sustainable treatment and utilization of nitrate for ammonia fuel production by strategically regulating the electron transfer pathway across the biotic‐abiotic interface. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
36. In Situ Stimulus Response Study on the Acetylene/Ethylene Purification Process in MOFs.
- Author
-
Cai, Li‐Zhen, Yu, Xu‐Ying, Wang, Ming‐Sheng, Yuan, Da‐Qiang, Chen, Wen‐Fa, Wu, Ming‐Yan, and Guo, Guo‐Cong
- Abstract
Efficient removal of acetylene (C2H2) impurities from polymer‐grade ethylene (C2H4) in a simple, clean manner remains a challenging goal in industry. The use of porous materials such as metal–organic frameworks (MOFs) is promising for this aim but the acquisition of high purification performance is still hindered by few knowledge on the purification process because the previous conclusions were derived basically from the non‐breakthrough tests or ignored the influence of structural difference (crystal structure, morphology, or defect). Here we propose an unprecedented in situ stimulus response strategy to minimize the influence of structural difference, obtain the gas‐loading crystal structures of the same MOF before and after light or heat stimulation, directly observe the evolution of pore charge distribution and pore⋅⋅⋅gas interactions under light/heat induction, and finally summarizes the favorable structure for highly efficient purification of C2H4. This study opens a new route to understand the relationship between the structure and separation performance for porous materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. A Supramolecular Organic Framework‐Mediated Electrochemical Strategy Achieves Highly Selective and Continuous Uranium Extraction.
- Author
-
Wang, Chaoyi, Xu, Meiyun, Wang, Wenwen, and Hua, Daoben
- Subjects
- *
CHARGE exchange , *ELECTROWINNING , *URANIUM , *URANINITE , *LOW voltage systems - Abstract
The integration of selectivity and electron transfer ability remains a primary challenge in developing electrode materials for uranium electroextraction. Herein, a phenanthroline‐based supramolecular organic framework (MPSOF) is elaborately constructed as a pioneering cathode material through the hydrogen bond‐driven self‐assembly of melamine and 1,10‐phenanthroline 2,9‐dicarboxylic acid (PDA) for selective and continuous electrochemical uranium extraction (EUE). PDA moieties selectively capture UO22+, while the hydrogen bond‐supporting frameworks provide an efficient electron transfer channel for the redox of UO22+. These structural features enable the rapid formation and spontaneous shedding of uranium precipitate from MPSOF, allowing for the regeneration of the selective adsorption sites. As a result, MPSOF‐mediated EUE exhibits a high extraction capacity of 7311 mg U g−1 at a low voltage of −3.5 V but does not reach equilibrium. Cyclic EUE is employed to uranium extraction from simulated high‐salt radioactive effluents and attains high selectivity for uranium. The electroextraction mechanism is confirmed, wherein uranium species transform into (UO2)O2·4H2O. This work not only provides an efficient electrode material for uranium electroextraction, but also presents a novel electrochemical strategy for separation and adsorption of other radionuclides and contaminant ions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Built‐In Electric Field Boost Photocatalytic Degradation of Pollutants in Wastewater.
- Author
-
Yu, Yang, Qiao, Zhiyong, and Ding, Changming
- Subjects
- *
PHOTODEGRADATION , *CHARGE exchange , *PHOTOCATALYSTS , *ELECTRIC fields , *SEWAGE , *PHOTOCATALYSIS - Abstract
The photocatalysis technique shows significant potential for wastewater degradation; however, the rapid recombination of photogenerated holes and electrons severely limits its photocatalytic efficiency. This situation necessitates the development of effective strategies to tackle these challenges. One well‐documented approach is built‐in electric field engineering in heterojunctions or composites, which has been shown to enhance electron transfer and thereby reduce the recombination of electrons and holes. This strategy has proven highly effective in significantly improving photocatalytic activity for the degradation of pollutants in wastewater. In this context, we summarize recent advancements in built‐in electric field engineering in photocatalysts, highlighting the fundamentals and modifications of this approach, as well as its positive impact on photocatalytic performance in the degradation of wastewater pollutants. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Reinforced Electrons Transfer and Capture in S‐Scheme TiO2@Co(OH)F‐Pt Heterojunction for Excellent Solar Hydrogen Evolution.
- Author
-
Li, Xinpei, Zhang, Wen, Yang, Fan, Yao, Shuang, Li, Lina, An, Xuguang, Xi, Baojuan, Xiong, Shenglin, and An, Changhua
- Subjects
- *
ELECTRON capture , *CHARGE exchange , *CONDUCTION bands , *CATALYTIC activity , *CHEMICAL energy , *CHARGE carriers - Abstract
TiO2 with the merits of non‐toxicity, high stability, strong redox capability, and low cost, has garnered considerable attention in the fields of renewable energy. However, the practical application is limited by the rapid recombination of photogenerated electron–hole pairs, posing a challenge to enhance electron utilization without compromising catalytic activity. Herein, S‐scheme TiO2@Co(OH)F‐Pt heterojunction through a simple hydrothermal and photo‐deposition method is constructed. The experimental tests and theoretical computation indicate that Co(OH)F possesses a smaller work function and a more negative conduction band (CB) position, significantly accelerating the separation of photogenerated charge carriers. Furthermore, the built‐in electric field, band bending between TiO2 and Co(OH)F, and the electron sink of Pt nanoparticles, facilitate the reduction of protons to hydrogen. The as‐prepared TiO2@Co(OH)F‐Pt exhibits high‐performance solar hydrogen evolution with an evolution rate of 1401 µmol h−1. The apparent quantum yield (AQY) is determined to be 22.8% at a single wavelength of 365 nm. After reacting 12 h for three cycles, no noticeable performance degradation occurs, showing good stability of the catalyst. This work provides a rational strategy for the design of heterojunction photocatalysts for driving the production of new energy and useful chemicals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. BCN‐Supported CoFe Alloy Catalysts for Enhanced C─C Coupling in Photothermocatalytic CO Hydrogenation.
- Author
-
Hao, Quanguo, Li, Zhenhua, Zhu, Yuhua, Shi, Yiqiu, Huo, Mengge, Yuan, Hong, Ouyang, Shuxin, and Zhang, Tierui
- Subjects
- *
COUPLING reactions (Chemistry) , *METAL catalysts , *TRANSITION metals , *CHARGE exchange , *CATALYST synthesis - Abstract
The high selectivity of C─C coupling reactions in Fischer–Tropsch synthesis (FTS) is often limited due to the difficulty in the regulation of transition metals acting as active sites to balance between C─C chain propagation and over hydrogenation. Herein, BCN‐supported CoFe alloy catalyst has been successfully constructed for promoting C─C chain propagation. When exposed to light irradiation, the CoFe‐BCN catalyst exhibits a higher CO conversion of 18.4% with the enhanced selectivity toward multi‐carbon (C2+) hydrocarbons that increases from 22.4% to 64.1%, and the reduced over hydrogenation to CH4 that decreases from 74.8% to 25.4% in contrast to Co‐BCN catalyst. Structural characterizations indicate that introducing Fe to create CoFe alloy can decrease the d‐band center of Co, which significantly promotes C─C coupling reactions but weakens hydrogenation in FTS process. The findings underscore the potential of modifying catalysts with metal atoms to optimize their electronic structure to regulate reaction pathways in CO hydrogenation for high‐value products formation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Electron Transfer from Encapsulated Fe3C to the Outermost N‐Doped Carbon Layer for Superior ORR.
- Author
-
Quílez‐Bermejo, Javier, Daouli, Ayoub, Dalí, Sergio García, Cui, Yingdan, Zitolo, Andrea, Castro‐Gutiérrez, Jimena, Emo, Mélanie, Izquierdo, Maria T., Mustain, William, Badawi, Michael, Celzard, Alain, and Fierro, Vanessa
- Subjects
- *
CARBON-based materials , *CHARGE exchange , *POWER density , *FUEL cells , *CATALYTIC activity , *OXYGEN reduction - Abstract
Encapsulating Fe3C in carbon layers has emerged as an innovative strategy for protecting Fe3C while preserving its high oxygen reduction activity. However, fundamental questions persist regarding the active sites of encapsulated Fe3C due to the restricted accessibility of oxygen molecules to the metal sites. Herein, the intrinsic electron transfer mechanisms of Fe3C nanoparticles encapsulated in N‐doped carbon materials are unveiled for oxygen reduction electrocatalysis. The precision‐structured C1N1 material is used to synthesize N‐doped carbons with encapsulated Fe3C, significantly enhancing catalytic activity (EONSET = 0.98 V) and achieving near‐100% operational stability. In anion‐exchange membrane fuel cells, an excellent peak power density of 830 mW cm−2 is reached at 60 °C. The experimental and computational results revealed that the presence of Fe3C cores dynamically triggers electron transfer to the outermost carbon layer. This phenomenon amplifies the oxygen reduction reaction performance at N sites, contributing significantly to the observed catalytic enhancement. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Ce-doped copper oxide and copper vanadate Cu3VO4 hybrid for boosting nitrate electroreduction to ammonia.
- Author
-
Zhang, Meng, Liu, Yang, Duan, Yun, Liu, Xu, and Wang, Yan-Qin
- Subjects
- *
COPPER , *CERIUM oxides , *VANADATES , *ELECTROLYTIC reduction , *DENITRIFICATION , *AMMONIA , *COPPER oxide , *DENSITY of states , *ELECTRONIC structure - Abstract
A Ce-Cu 2+1 O/Cu 3 VO 4 -CF catalyst was successfully fabricated for efficient electrocatalytic nitrate reduction to ammonia, which demonstrates remarkable performance under alkaline conditions, achieving an NH 3 Faradaic efficiency (FE) of 93.7% at −0.5 V (vs. RHE), with an NH 3 production rate of 18.905 mg/h cm−2. [Display omitted] • A Ce doped Cu 2+1 O/Cu 3 VO 4 -CF electrocatalyst is first reported. • Ce-Cu 2+1 O/Cu 3 VO 4 -CF shows superior electrocatalytic NO 3 RR performance. • Ce-doping adjusts the density of states of the catalyst and creates more O v , which promotes the NO 3 RR activity. • DFT calculations further reveal the changes the d-band center and the rate-degerming step. The electrocatalytic nitrate reduction to ammonia reaction (ENO 3 RR) holds great potential as a cost-effective method for synthesizing ammonia. This work designed a cerium (Ce) doped Cu 2+1 O/Cu 3 VO 4 catalyst. The coupling of vanadium-based oxides with Cu 2+1 O effectively adjusts the catalyst's electronic structure, addressing the inherent issues of limited activity and low conductivity in typical copper-based oxides; moreover, Ce doping generates oxygen vacancies (O v), providing more active sites and thereby enhancing the ENO 3 RR performance. The catalyst exhibits superior NH 3 Faradaic efficiency (93.7 %) with a NH 3 yield of 18.905 mg h−1 cm−2 at −0.5 V vs. RHE under alkaline conditions. This study provides guidance for the design of highly efficient catalysts for ENO 3 RR. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Pt-O-Ce interaction enhanced by Al substitution to promote the acetone degradation through accelerating the breaking of C[sbnd]C bond in acetic acid intermediate.
- Author
-
Zhang, Wan-Peng, Li, Ying-Ying, Zhao, Junyi, Wu, Kun, Xiao, Hang, and Li, Jian-Rong
- Subjects
- *
ACETIC acid , *ACTIVATION energy , *ACETONE , *VOLATILE organic compounds , *CERIUM oxides , *CHARGE exchange - Abstract
[Display omitted] The reaction rate of volatile organic compounds (VOCs) oxidation is controlled by the rate-limiting step in the total reaction process. This study proposes a novel strategy, by which the rate-limiting step of acetone oxidation is accelerated by enhanced chemical bond interaction with more electrons transfer through Al-substituted CeO 2 loaded Pt (Pt/Al-CeO 2). Results indicate that the rate-limiting step in the process of acetone oxidation is the decomposition of acetic acid. Al substitution enhances the Pt-O-Ce interaction that transfers more electrons from Pt/Al-CeO 2 to acetic acid, promoting the breaking of its C C bond with a lower free energy barrier. Attributing to these, the reaction rate of Pt/Al-CeO 2 is 13 times as high as that of Pt/CeO 2 and its TOF Pt value is 11 times as high as that of Pt/CeO 2 at 150 °C. Moreover, the CO 2 selectivity of Pt/Al-CeO 2 also increases by 22 %. This work establishes the relationship between Pt-O-Ce interaction and acetone oxidation that provides novel perspectives on the development of efficient materials for VOCs oxidation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Theoretical Hints to Optimize Energy Dissipation and Cell–Cell Response in Quantum Cellular Automata Based on Tetrameric and Bidimeric Cells †.
- Author
-
Palii, Andrew, Zilberg, Shmuel, and Tsukerblat, Boris
- Subjects
VIBRONIC coupling ,ELECTRON delocalization ,CHARGE exchange ,COMPUTER-assisted molecular design ,EXCESS electrons - Abstract
This article is largely oriented towards the theoretical foundations of the rational design of molecular cells for quantum cellular automata (QCA) devices with optimized properties. We apply the vibronic approach to the analysis of the two key properties of such molecular cells, namely the cell–cell response and energy dissipation in the course of the non-adiabatic switching of the electric field acting on the cell. We consider two kinds of square planar cells, namely cells represented by a two-electron tetrameric mixed valence (MV) cluster and bidimeric cells composed of two one-electron MV dimeric half-cells. The model includes vibronic coupling of the excess electrons with the breathing modes of the redox sites, electron transfer, intracell interelectronic Coulomb repulsion, and also the interaction of the cell with the electric field of polarized neighboring cells. For both kinds of cells, the heat release is shown to be minimal in the case of strong delocalization of excess electrons (weak vibronic coupling and/or strong electron transfer) exposed to a weak electric field. On the other hand, such a parametric regime proves to be incompatible with a strong nonlinear cell–cell response. To reach a compromise between low energy dissipation and a strong cell–cell response, we suggest using weakly interacting MV molecules with weak electron delocalization as cells. From this point of view, bidimeric cells are advantageous over tetrameric ones due to their smaller number of electron transfer pathways, resulting in a lower extent of electron delocalization. The distinct features of bidimeric cells, such as their two possible mutual arrangements ("side-by-side" and "head-to-tail"), are discussed as well. Finally, we briefly discuss some relevant results from a recent ab initio study on electron transfer and vibronic coupling from the perspective of the possibility of controlling the key parameters of molecular QCA cells. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. An active learning workflow for predicting hydrogen atom adsorption energies on binary oxides based on local electronic transfer features.
- Author
-
Wenhao Jing, Zihao Jiao, Mengmeng Song, Ya Liu, and Liejin Guo
- Subjects
WORKFLOW ,CHARGE exchange ,DENSITY functional theory ,OXIDES ,ABSTRACTION reactions ,MACHINE learning ,COORDINATION polymers - Abstract
Machine learning combined with density functional theory (DFT) enables rapid exploration of catalyst descriptors space such as adsorption energy, facilitating rapid and effective catalyst screening. However, there is still a lack of models for predicting adsorption energies on oxides, due to the complexity of elemental species and the ambiguous coordination environment. This work proposes an active learning workflow (LeNN) founded on local electronic transfer features (e) and the principle of coordinate rotation invariance. By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures, LeNN mitigates abrupt feature changes due to different element types and clarifies coordination environments. As a result, it enables the prediction of *H adsorption energy on binary oxide surfaces with a mean absolute error (MAE) below 0.18 eV. Moreover, we incorporate local coverage (θ1) and leverage neutral network ensemble to establish an active learning workflow, attaining a prediction MAE below 0.2 eV for 5419 multi-*H adsorption structures. These findings validate the universality and capability of the proposed features in predicting *H adsorption energy on binary oxide surfaces. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Electrogenic performance and carbon sequestration potential of biophotovoltaics.
- Author
-
Sun, Haitang, Xie, Xuan, and Ding, Jing
- Abstract
Biophotovoltaics (BPV) is a clean and sustainable solar energy generation technology that operates by utilizing photosynthetic autotrophic microorganisms to capture light energy and generate electricity. However, a major challenge faced by BPV systems is the relatively low electron transfer efficiency from the photosystem to the extracellular electrode, which limits its electrical output. Additionally, the transfer mechanisms of photosynthetic microorganism metabolites in the entire system are still not fully clear. In response to this, this article briefly introduces the basic BPV principles, reviews its development history, and summarizes measures to optimize its electrogenic efficiency. Furthermore, recent studies have found that constructing photosynthetic-electrogenic microbial consortia can achieve high power density and stability in BPV systems. Therefore, the article discusses the potential application of constructing photosynthetic-electrogenic microbial aggregates in BPV systems. Since photosynthetic-electrogenic microbial communities can also exist in natural ecosystems, their potential contribution to the carbon cycle is worth further attention. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Peptides and metal ions: A successful marriage for developing artificial metalloproteins.
- Author
-
Leone, Linda, De Fenza, Maria, Esposito, Alessandra, Maglio, Ornella, Nastri, Flavia, and Lombardi, Angela
- Abstract
The mutual relationship between peptides and metal ions enables metalloproteins to have crucial roles in biological systems, including structural, sensing, electron transport, and catalytic functions. The effort to reproduce or/and enhance these roles, or even to create unprecedented functions, is the focus of protein design, the first step toward the comprehension of the complex machinery of nature. Nowadays, protein design allows the building of sophisticated scaffolds, with novel functions and exceptional stability. Recent progress in metalloprotein design has led to the building of peptides/proteins capable of orchestrating the desired functions of different metal cofactors. The structural diversity of peptides allows proper selection of first‐ and second‐shell ligands, as well as long‐range electrostatic and hydrophobic interactions, which represent precious tools for tuning metal properties. The scope of this review is to discuss the construction of metal sites in de novo designed and miniaturized scaffolds. Selected examples of mono‐, di‐, and multi‐nuclear binding sites, from the last 20 years will be described in an effort to highlight key artificial models of catalytic or electron‐transfer metalloproteins. The authors' goal is to make readers feel like guests at the marriage between peptides and metal ions while offering sources of inspiration for future architects of innovative, artificial metalloproteins. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Enhancement of the anaerobic biodegradation efficiency of azo dye by anthraquinone-loaded biochar biofilm: factors affecting biofilm formation and the enhancement mechanism
- Author
-
Guangyuan Wang, Chenhao Cui, Yuqian Wang, Jiwei Pang, Shanshan Yang, Chuandong Wu, Rui Fang, Luyan Zhang, Nanqi Ren, and Jie Ding
- Subjects
Azo dye biodegradation ,AQS-loaded biochar ,Biofilm formation ,Electron transfer ,Inoculation conditions ,Environmental sciences ,GE1-350 ,Agriculture - Abstract
Abstract Carbon-based materials that serve as microbial carriers, and the role of surface-formed biofilms in anaerobic digestion, merit further investigation. This study explored the role and mechanism behind the biodegradation enhancement of biofilms formed onto anthraquinone-loaded biochar (AQS-BC) surfaces through the anaerobic decolorization process of azo dye Reactive Red 2, and optimized the conditions for AQS-BC biofilm formation. The results indicated that the AQS-BC biofilm system exhibited high treatment efficiency and stability in RR2 anaerobic decolorization. RR2 led to the accumulation of volatile fatty acids (VFAs) and inhibition of methane production, while the presence of AQS increased methane production. The effects of sludge concentration, contact time, carbon source concentration, and RR2 concentration on biofilm maturity were also analyzed. Combining biochemical characteristics, electrochemical properties, surface structure, and microbial community analysis, a mechanism for the anaerobic decolorization of RR2 via AQS-BC as a microbial carrier was proposed. This study provides insights into the roles of biofilms in the anaerobic wastewater treatment processes. Graphical Abstract
- Published
- 2024
- Full Text
- View/download PDF
49. Controlled electron transfer by molecular wires embedded in ultrathin insulating membranes for driving redox catalysis
- Author
-
Frei, Heinz
- Subjects
Plant Biology ,Biochemistry and Cell Biology ,Biological Sciences ,Affordable and Clean Energy ,Climate Action ,Electron transfer ,Molecular wires ,Photocatalysis ,Proton transport ,Redox catalysis ,Ultrathin membranes ,Genetics ,Plant Biology & Botany ,Biochemistry and cell biology ,Plant biology - Abstract
Organic bilayers or amorphous silica films of a few nanometer thickness featuring embedded molecular wires offer opportunities for chemically separating while at the same time electronically connecting photo- or electrocatalytic components. Such ultrathin membranes enable the integration of components for which direct coupling is not sufficiently efficient or stable. Photoelectrocatalytic systems for the generation or utilization of renewable energy are among the most prominent ones for which ultrathin separation layers open up new approaches for component integration for improving efficiency. Recent advances in the assembly and spectroscopic, microscopic, and photoelectrochemical characterization have enabled the systematic optimization of the structure, energetics, and density of embedded molecular wires for maximum charge transfer efficiency. The progress enables interfacial designs for the nanoscale integration of the incompatible oxidation and reduction catalysis environments of artificial photosystems and of microbial (or biomolecular)-abiotic systems for renewable energy.
- Published
- 2023
50. Rapid-reaction kinetics of the bifurcating NAD+-dependent NADPH:ferredoxin oxidoreductase NfnI from Pyrococcus furiosus
- Author
-
Ortiz, Steve, Niks, Dimitri, Wiley, Seth, Lubner, Carolyn E, and Hille, Russ
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Ferredoxins ,Kinetics ,NAD ,NADP ,Oxidation-Reduction ,Oxidoreductases ,Pyrococcus furiosus ,Archaeal Proteins ,electron bifurcation ,electron paramagnetic resonance ,electron transfer ,flavoprotein ,Chemical Sciences ,Medical and Health Sciences ,Biochemistry & Molecular Biology ,Biological sciences ,Biomedical and clinical sciences ,Chemical sciences - Abstract
We have investigated the kinetics of NAD+-dependent NADPH:ferredoxin oxidoreductase (NfnI), a bifurcating transhydrogenase that takes two electron pairs from NADPH to reduce two ferredoxins and one NAD+ through successive bifurcation events. NADPH reduction takes place at the bifurcating FAD of NfnI's large subunit, with high-potential electrons transferred to the [2Fe-2S] cluster and S-FADH of the small subunit, ultimately on to NAD+; low-potential electrons are transferred to two [4Fe-4S] clusters of the large subunit and on to ferredoxin. Reduction of NfnI by NADPH goes to completion only at higher pH, with a limiting kred of 36 ± 1.6 s-1 and apparent KdNADPH of 5 ± 1.2 μM. Reduction of one of the [4Fe-4S] clusters of NfnI occurs within a second, indicating that in the absence of NAD+, the system can bifurcate and generate low-potential electrons without NAD+. When enzyme is reduced by NADPH in the absence of NAD+ but the presence of ferredoxin, up to three equivalents of ferredoxin become reduced, although the reaction is considerably slower than seen during steady-state turnover. Bifurcation appears to be limited by transfer of the first, high-potential electron into the high-potential pathway. Ferredoxin reduction without NAD+ demonstrates that electron bifurcation is an intrinsic property of the bifurcating FAD and is not dependent on the simultaneous presence of NAD+ and ferredoxin. The tight coupling between NAD+ and ferredoxin reduction observed under multiple-turnover conditions is instead simply due to the need to remove reducing equivalents from the high-potential electron pathway under multiple-turnover conditions.
- Published
- 2023
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.