Search

Photosynthesis of hydrogen peroxide (H2O2) is regarded as an economically efficient and environmentally friendly synthesis method. However, the scalability of photocatalytic H2O2 production (PHP) is hindered by the sluggish reaction kinetics and rapid recombination of photogenerated charge carriers. In this study, an organic amine‐constrained ions intercalated carbon nitride/CdSe‐diethylenetriamine (K+/I−‐CN/CdSe‐D) S‐scheme heterojunction is synthesized using an organic–inorganic hybrid approach and employed for PHP for the first time. The optimization of the heterojunction interface by I− and K+ ions contributed to enhanced light absorption capabilities and reduced interlayer charge transfer distance. Concurrently, the synergy of C─Se bonds at interface effectively modulated the electron transfer pathways. The coordination environment and charge transfer mechanism are thoroughly investigated by extended X‐ray absorption fine structure and in situ irradiated X‐ray photoelectron spectroscopy. The H2O2 production rate of 40%K+/I−‐CN/CdSe‐D reached 2240.23 µmol h−1 g−1 in pure water. This study highlights the significance of dual tuning of interface chemical bonds and ionic intercalation as an effective strategy for enhancing the photocatalytic H2O2 , paving the way for further advancements in PHP technology. [ABSTRACT FROM AUTHOR]

The quick recombination of photogenerated carriers and the high surface reaction barrier are two important aspects influencing photocatalytic hydrogen generation. In this paper, a sulfur vacancy-modified two-dimensional (2D) fluorinated-TiO2 nanosheet/Mn0.2Cd0.8S (F-TiO2/MCS) S-scheme heterojunction was synthesized by a simple hydrothermal method to accelerate photogenerated electron transfer. The formation of an S-scheme heterojunction between MCS nanoflowers and 2D F-TiO2 enhances the efficacy of photocatalytic hydrogen generation by facilitating the separation of photogenerated electron–hole pairs. Meanwhile, the sulfur vacancies of F-TiO2/MCS change the local electronic structure of the heterojunction surface by capturing photogenerated electrons, resulting in a photocatalytic hydrogen evolution rate for F-TiO2/MCS of 3197 μmol g–1 h–1, which is 4.42 times greater than that of the pure MCS. Experimental measurements and density functional theory (DFT) calculations show that the mutual synergy between the S-scheme heterojunction and the sulfur vacancies not only provides abundant H2 adsorption active sites but also promotes interfacial charge separation and migration, which improves the photocatalytic performance of the F-TiO2/MCS composite. This work holds significance for the photocatalytic hydrogen production of sulfur vacancy-modified S-scheme heterojunctions. [ABSTRACT FROM AUTHOR]

The S‐scheme heterojunctions have great potential for photocatalytic carbon dioxide reduction due to their unique carrier migration pathways, superior carrier separation efficiencies, and high redox capacities. However, the precise process of the oriented powerful electron transport remains a great challenge. Herein, an InOCd bond‐modulated S‐scheme heterojunction of In2O3/CdSe‐DETA is synthesized by a simple microwave‐assisted hydrothermal method for the accelerated photogenerated electron transfer. Meanwhile, the oxygen vacancies (Vo) of In2O3 have an electron capture effect. Consequently, thanks to the synergistic effect of this In‐Vo‐In‐O‐Cd structural units at the interface, electrons are extracted and rapidly transferred to the surface‐active sites, which improves the electronic coupling of CO2. This finding precisely adjusts the electron transfer pathway and shortens the electron transfer distance. The synergistic effect of this chemical bond established in the S‐scheme heterostructure with oxygen vacancies in In2O3 (Vo‐In2O3) provides new insights into photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

The design of Z-scheme heterostructure photocatalysts provides a promising route to effectively degrade organic pollutants in wastewater. Herein, novel Z-scheme SnS2/Ag3VO4 heterojunction photocatalysts were prepared for the first time via a simple precipitation method. The microstructures and physicochemical properties of the SnS2/Ag3VO4 nanohybrids were carefully researched using various analytical instruments. The photocatalytic characteristics of the SnS2/Ag3VO4 heterojunction were researched using decomposition of methylene blue (MB). Outcomes showed that 5 wt% SnS2/Ag3VO4 hybrid photocatalysts possessed higher photocatalytic activity and better stability than the pure sample. The significant improvements were attributed to the establishment of a Z-scheme heterojunction between SnS2 and Ag3VO4, which effectively facilitated the segregation and transportation of photocarriers, as proved by photoluminescence (PL) spectra and photoelectrochemical tests. Besides, trapping experiments combined with electronic spin resonance (ESR) tests were applied to detect the dominant active species involved in MB removal. Additionally, the Z-scheme mechanism was put forward to explain the outstanding activity of the SnS2/Ag3VO4 system. [ABSTRACT FROM AUTHOR]

The rational design of heteronuclear dual‐atom catalyst (DAC) is intricate due to the random dispersion of metal atoms under thermal treatment. Herein, a novel precursor pre‐orientation strategy is reported to construct Fe‐Co diatomic sites atomically dispersed on nitrogen doped carbon (Fe‐Co‐NC) via cubic Prussian blue analogue as metal source. Due to the specific synergy between Fe and Co centers, the obtained Fe‐Co‐NC catalyst renders outstanding oxygen reduction reaction (ORR) performance with positive half‐wave potential and good durability in wide pH range. Density functional theory further clarifies the active centers and reveals that the Fe‐Co‐NC dual atomic catalyst follows the modulation mechanism, where the intermediates tended to adsorb on Fe site, while the neighboring Co atom can assist by lowering the d‐band center of Fe site. Experimentally and theoretically emphasizes the priority of heteronuclear diatomic Fe‐Co catalysts over homonuclear Fe‐Fe‐NC and Co‐Co‐NC DAC. Moreover, the Zn‐Air battery (ZAB) and microbial fuel cell (MFC) assembled with Fe‐Co‐NC cathodes both exhibit splendid power density (382 mW cm−2 for ZAB, 2034 ± 103 mW m−2 for MFC) as well as excellent stability. This work provides a new perspective for rational construction and precise regulation for heteronuclear dual‐atom catalysts. [ABSTRACT FROM AUTHOR]

Although atomically dispersed Fe‐N4 on carbon materials (Fe‐NC) have enormous potential for the oxygen reduction reaction (ORR), precise control over the electronic structure of Fe to enhance the catalytic performance and a full understanding of the catalytic mechanism remain elusive. Herein, a novel approach is designed to boost the kinetic activity of single Fe‐N4 centers by controlling S‐doped content and species (namely, thiophene‐like S and oxidized S). Due to confinement and catalysis effects, the innovative strategy of combining a Mg(OH)2 template with KOH activation preferentially generates oxidized S and simultaneously constructs porous carbon with a high Fe loading (2.93 wt%) and hierarchical pores. Theoretical calculations suggest that neighboring S functionalities can affect the electronic configurations of Fe‐N4 sites and increase the electron density around Fe atoms, thereby optimizing the adsorption energy of intermediates and substantially accelerating reaction kinetics, following the trend: oxidized S doped > thiophene‐like S doped > pristine Fe‐N4. Benefiting from high activity and accessibility of Fe‐N4 sites, the optimal FeNC‐SN‐2 electrode displays impressive ORR activity with large power density while maintaining outstanding durability in Zn‐air batteries and microbial fuel cells. The work paves the way to prepare stable single‐atom metal‐Nx sites with heteroatom‐doping for diverse high‐performance applications. [ABSTRACT FROM AUTHOR]

Used as high‐performance electrodes, both structural and compositional alterations of carbon materials play very important roles in energy conversion/storage devices. Especially in supercapacitors, hierarchical pores and heteroatom doping in carbon materials are indispensable. Here the rambutan‐like hierarchically porous carbon microspheres (PCMs) have been constructed via a hydrothermal treatment, followed by carbonization/activation. The hierarchically porous microstructure is composed of three‐dimensional porous carbon networks, which give rise to a large surface area. Moreover, N and O functional groups are introduced in the as‐prepared samples, which could generate the extra pseudocapacitance. Benefitting from the interconnected hierarchical and open structure, PCM exhibits outstanding capacitive performance, for example, superior specific capacitance and rate capability (397 and 288 F g−1 at 0.5 and 20 A g−1, respectively), as well as long cycling stability (about 95% capacitance retention after 10,000 cycles). These encouraging results may pave an efficient way to fabricate advanced supercapacitors in the future. [ABSTRACT FROM AUTHOR]

Paraquat (PQ) has been demonstrated that the main target organ for the toxicity is the lung. This study aimed to investigate the potential protective effect of PDTC on the PQ-induced pulmonary damage. Fifty-four rats were divided into control, PQ- treated and PQ+PDTC-treated groups. Rats in the PQ group were administrated 40 mg/kg PQ by gastric gavage, and PDTC group with 40 mg/kg PQ followed by injection of 120 mg/kg PDTC (IP). On the days 3,7, 14 and 21 after treatments, the activities of GSH-Px, SOD, MDA level and the content of HYP were measured. TGF-β1 mRNA and protein were assayed by RT-PCR and ELISA. MDA level in plasma and BALF was increased and the activities of GSH-Px and SOD were decreased significantly in the PQ- treated groups (P < .05) compared with control group. While the activities of GSH-Px and SOD in the PQ+PDTC-treated groups was markedly higher than that of PQ-treated groups (P < .05), and in contrast, MDA level was lower. TGF-β1 mRNA and protein were significantly lower in the PQ+PDTC-treated groups than that of PQ-treated groups (P < .05). The histopathological changes in the PQ+PDTC-treated groups were milder than those of PQ groups. Our results suggested that PDTC treatment significantly attenuated paraquat-induced pulmonary damage. Copyright [C] 2009 Xiuli Chang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., 1. Introduction Paraquat (PQ) is a nonselective contact herbicide, which is used world-widely for its high efficiency and low residues in the crops. It has been extensively demonstrated that it [...]

Electrochemical CO 2 reduction into high-value-added formic acid/formate is an attractive strategy to mitigate global warming and achieve energy sustainability. However, the adsorption energy of most catalysts for the key intermediate *OCHO is usually weak, and how to rationally optimize the adsorption of *OCHO is challenging. Here, an effective Bi-Sn bimetallic electrocatalyst (Bi 1 -O-Sn 1 @C) where a Bi-O-Sn bridge-type nanostructure is constructed with O as an electron bridge is reported. The electronic structure of Sn is precisely tuned by electron transfer from Bi to Sn through O bridge, resulting in the optimal adsorption energy of intermediate *OCHO on the surface of Sn and the enhanced activity for formate production. Thus, the Bi 1 -O-Sn 1 @C exhibits an excellent Faradaic efficiency (FE) of 97.7% at -1.1 V (vs RHE) for CO 2 reduction to formate (HCOO - ) and a high current density of 310 mA cm -2 at -1.5 V, which is one of the best results catalyzed by Bi- and Sn-based catalysts reported previously. Impressively, the FE exceeds 93% at a wide potential range from -0.9 to -1.4 V. In-situ ATR-FTIR, in-situ Raman, and DFT calculations confirm the unique role of the bridge-type structure of Bi-O-Sn in highly efficient electrocatalytic reduction of CO 2 into formate., (© 2023 Wiley-VCH GmbH.)