Search

It is a novel-effective process for realizing high-efficiency sensing and continuous gas monitoring by introducing precious metals into metal–oxide–semiconductors (MOSs). In this study, Ag is exploited to prepare surface functionalized SnO2 nanoparticles (NPs) and innovative xAg@SnO2/CsPbBr3, activating and catalyzing the gas sensing reactions on semiconductors. The results show that the precious metal Ag NPs promote the directional transport of carriers, thus improving the gas sensing performances. In addition, innovative xAg@SnO2/CsPbBr3 composites originated from Ag@SnO2 NPs and 3-mercaptopropionic acid treated all-inorganic perovskite CsPbBr3 are constructed to further accelerate electron transfer on heterointerfaces, enabling continuous and efficient monitoring of ethanolamine (EA) at room temperature. The sensing properties of Ag@SnO2/CsPbBr3 on various volatile organic compounds are investigated. Compared with pure CsPbBr3, the EA response of as-prepared 2Ag@SnO2/CsPbBr3 is obviously improved by about sevenfold. The response/recovery time is greatly shortened, besides the good stability. Another interesting result for xAg@SnO2/CsPbBr3 is the lower limit of detection of 44.43 ppb. The work demonstrates that Ag modification facilitates the adsorption/desorption rate and the response. Furthermore, the catalytic activation of noble metal Ag NPs and the synergistic interaction of SnO2/CsPbBr3 nano-heterojunctions promote EA sensing performances at room temperature. [ABSTRACT FROM AUTHOR]

Purpose: When planning guided implant surgery, highly radiopaque materials such as metals or zirconia produce streaking artifacts ('metal artifact') on cone‐beam computed tomography scans, which can impair registration of the intraoral scan. This study aimed to determine the effect of metal artifact reduction on the trueness of registration in the presence of multiple full‐coverage zirconia crowns. Materials and methods: A 3D‐printed maxillary study model was restored with 12 full‐coverage zirconia crowns and scanned with an intraoral scanner. Cone‐beam computed tomography scans of the study model were acquired, with and without activation of the metal artifact reduction algorithm. Registration of the optical scans was performed using initial point‐based registration with surface‐based refinement, and the deviation was measured at four pre‐defined dental landmarks. Welch's t‐test was used to compare the registration error for the metal artifact reduction group with the control group. Results: The average registration error was 0.519 mm (95% CI 0.507 to 0.531) with metal artifact reduction deactivated, compared to 0.478 mm (95% CI 0.460 to 0.496) without metal artifact reduction. Therefore, activation of the metal artifact reduction algorithm was associated with a 0.041 mm (95% CI 0.020 to 0.061, p < 0.001) increase in average registration error. Conclusions: The use of the metal artifact reduction algorithm slightly reduced trueness in this in vitro study. Clinicians are advised not to rely on a metal artifact reduction (MAR) algorithm for registration of a cone‐beam computed tomography scan with an intraoral scan when planning guided implant surgery in the presence of restoration artifacts. [ABSTRACT FROM AUTHOR]

This work proposes for the first time protecting–reflecting on both sides of plated mirrors and a solution to polycarbonate surface vulnerability to weathering and scratching using tungsten disulfide (WS2) by mechanical polishing. The ability of the dynamic chemical plating (DCP) technique to deposit Ag films at the nanometer scale on a polycarbonate (PC) substrate and its characteristics to be metallized is also shown. These deposits hold significant promise for concentrated solar power (CSP) applications. Complementarily, the application of WS2 as a reflective film for CSP by mechanical polishing on smooth polycarbonate surfaces is both novel and practical. This technique is innovative and scalable without needing reactants or electrical potential, making it highly applicable in real-world scenarios, including, potentially, on-site maintenance. The effects of surface morphology and adhesion, and the reflectivity parameters of the silver metallic surfaces were investigated. Wettability was investigated because it is important for polymeric surfaces in the activation and metal deposition immediately after redox reactions. The flame technique improved wettability by modifying the surface with carbonyl and carboxyl functional groups, with PC among the few industrial polymers that resisted such a part of the process. The change in the chemical composition, roughness, and wettability of the surfaces effectively improved the adhesion between the Ag film and the PC substrate. However, it did not significantly affect the adhesion between PC and WS2 and showed its possible implementation as a first surface mirror. Overall, this work provides a scalable, innovative method for improving the durability and reflectivity of polycarbonate-based mirrors, with significant implications for CSP applications. [ABSTRACT FROM AUTHOR]

The recycled conductive agent (left) was able to be nitrogen doped by nitrogen-cooled plasma treatment to become an effective ORR/OER bifunctional catalyst (right). [Display omitted] • ORR/OER catalyst is prepared using discarded Li batteries. • Cold plasma treatment leads to a larger specific surface area. • Enhanced catalyst for ORR and OER. • Zinc-air batteries achieve 640 mAh/g capacity and 92 mW cm−2 power density. • Aqueous zinc-air batteries are capable of stable charge/discharge cycles of 100 h. Considerable amount of high-value transition metals components can be recycled in spent ternary lithium-ion batteries. In this study, we utilized the conductive agent carbon black, obtained from the leaching waste resulting from the chemical recovery of spent lithium-nickel-manganese-cobalt (NCM) oxide cathode materials. This process allows us to create valuable bifunctional catalysts for the oxygen reduction reaction and oxygen evolution reaction (ORR/OER), facilitated by a facile cold plasma activation method, as a part of lithium batteries circular economy. The activated conductive agent (RCA-30) exhibited an ORR half-wave potential of 0.74 V (vs. RHE) in 0.1 mol/L KOH solution, and an OER overpotential of 360 mV at 10 mA cm-2 in 1 mol/L KOH electrolyte, owing to nitrogen doping of carbon black and activation of surface metal oxides. The complete zinc-air batteries incorporating the activated catalysts at the cathode exhibited an open circuit potential of up to 1.48 V and sustained cycling for 100 h at a current density of 5 mA cm-2. Additionally, the activated catalysts contributed to a power density of 92 mW cm-2 and a full discharge capacity of 640 mAh/g. [ABSTRACT FROM AUTHOR]

C−H bond activation reactions facilitate highly efficient molecular transformations without requiring pre‐activating substrates. While the majority of reported reaction systems for C−H activation rely on metal complexes, certain reactions have demonstrated unique or superior catalysis of metal nanoparticles. This Concept article seeks to delineate recent reports that examine the novel catalysis and design strategy of supported metal nanoparticles for C−H bond activation reactions. These reactions include oxidative homocoupling of arenes, dehydrogenative alkylation of benzenes, selective H/D exchange reactions, and α,β‐dehydrogenation of ketones. [ABSTRACT FROM AUTHOR]

Titanium (Ti), as a hard tissue implant, is facing a big challenge for rapid and stable osseointegration owing to its intrinsic bio-inertness. Meanwile, surface-related infection is also a serious threat. In this study, large-scale quasi-vertically aligned sodium titanate nanowire (SNW) arrayed coatings incorporated with bioactive Cu2+ ions were fabricated through a compound process involving acid etching, hydrothermal treatment (HT), and ion exchange (IE). A novel coating based on sustained ion release and a shape-preserving design is successfully obtained. Cu2+ substituted Na+ in sodium titanate lattice to generate Cu-doped SNW (CNW), which maintains the micro-structure and phase components of the original SNW, and can be efficiently released from the structure by immersing them in physiological saline (PS) solutions, ensuring superior long-term structural stability. The synergistic effects of the acid etching, bidirectional cogrowth, and solution-strengthening mechanisms endow the coating with higher bonding strengths. In vitro antibacterial tests demonstrated that the CNW coatings exhibited effective good antibacterial properties against both Gram-positive and Gram-negative bacteria based on the continuous slow release of copper ions. This is an exciting attempt to achieve topographic, hydrophilic, and antibacterial activation of metal implants, demonstrating a paradigm for the activation of coatings without dissolution and providing new insights into insoluble ceramic-coated implants with high bonding strengths. [ABSTRACT FROM AUTHOR]

Gaining mechanistic understanding of oxygen activation on metal surfaces is a topical area of research in surface science. However, direct investigation of on‐surface oxidation processes at the nanoscale and the empirical validation of oxygen activation pathways remain challenging for the conventional analytical tools. In this study, we applied tip‐enhanced Raman spectroscopy (TERS) to gain mechanistic insights into oxygen activation on bulk Au(111) surface. Specifically, oxidation of 4‐aminothiophenol (4‐ATP) to 4‐nitrothiophenol (4‐NTP) on Au(111) surface was investigated using hyperspectral TERS imaging. Nanoscale TERS images revealed a markedly higher oxidation efficiency in disordered 4‐ATP adlayers compared to the ordered adlayers signifying that the oxidation of 4‐ATP molecules proceeds via interaction with the on‐surface oxidative species. These results were further validated via direct oxidation of the 4‐ATP adlayers with H2O2 solution. Finally, TERS measurements of oxidized 4‐ATP adlayers in the presence of H2O18 provided the first empirical evidence for the generation of oxidative species on bulk Au(111) surface via water‐mediated activation of molecular oxygen. This study expands our mechanistic understanding of oxidation chemistry on bulk Au surface by elucidating the oxygen activation pathway. [ABSTRACT FROM AUTHOR]

Persulfate-based advanced oxidation processes (PS-AOPs) have been widely investigated by academia and industry due to their high efficiency and selectivity for the removal of trace organic pollutants from complex water substrates. PS-AOPs have been extensively studied for the degradation of pesticides, drugs, halogen compounds, dyes, and other pollutants. Utilizing bibliometric statistics, this review presents a comprehensive overview of persulfate-based advanced oxidation technology research over the past decade. The number of published articles about persulfate activation has steadily increased during this time, reflecting extensive international collaboration. Furthermore, this review introduces the most widely employed strategies for persulfate activation reported in the past 10 years, including carbon material activation, photocatalysis, transition metal activation, electrochemical activation, ultrasonic activation, thermal activation, and alkali activation. Next, the potential activation mechanisms and influencing factors, such as persulfate dosage during activation, are discussed. Finally, the application of PS-AOPs in wastewater treatment and in situ groundwater treatment is examined. This review summarizes the previously reported experiences of persulfate-based advanced oxidation technology and presents the current application status of PS-AOPs in organic pollution removal, with the aim of avoiding misunderstandings and providing a solid foundation for future research on the removal of organic pollutants. [ABSTRACT FROM AUTHOR]

This work focuses on the comparison of H2 evolution in the hydrolysis of boron-containing hydrides (NaBH4, NH3BH3, and (CH2NH2BH3)2) over the Co metal catalyst and the Co3O4-based catalysts. The Co3O4 catalysts were activated in the reaction medium, and a small amount of CuO was added to activate Co3O4 under the action of weaker reducers (NH3BH3, (CH2NH2BH3)2). The high activity of Co3O4 has been previously associated with its reduced states (nanosized CoBn). The performed DFT modeling shows that activating water on the metal-like surface requires overcoming a higher energy barrier compared to hydride activation. The novelty of this study lies in its focus on understanding the impact of the remaining cobalt oxide phase. The XRD, TPR H2, TEM, Raman, and ATR FTIR confirm the formation of oxygen vacancies in the Co3O4 structure in the reaction medium, which increases the amount of adsorbed water. The kinetic isotopic effect measurements in D2O, as well as DFT modeling, reveal differences in water activation between Co and Co3O4-based catalysts. It can be assumed that the oxide phase serves not only as a precursor and support for the reduced nanosized cobalt active component but also as a key catalyst component that improves water activation. [ABSTRACT FROM AUTHOR]

As the widely used ultraviolet (UV) filter, Ensulizole (ELZ), has been proven as an environmental hormone, development of useful techniques for eliminating ELZ is imperative. Since SO4·−-based oxidation technologies are promising for treating emerging contaminants, and cobalt (Co) appears to be an extremely useful catalyst for monopersulfate (MPS) activation, that would be critical to construct advantageous cobaltic catalyst of MPS activation. A unique activator would be derived from a special metal organic framework ([Co]pyrazine[Ni(CN)4]) which is carbonized to become a nanocluster comprised of CoNi alloy nanoparticles (NPs) confined in carbon nanospheres, and nanotubes, forming CoNi@Carbon (CNC). Such a CNC nanocomposite would exhibit several promising properties: (1) as Co is the extremely effective metal for MPS activation, CoNi is expected for offering superior performance for activating MPS; (2) high magnetization of CoNi alloy would equip CNC with a magnetically-controllability; (3) CoNi encapsulated in carbon is guarded to enhance its reusability; (4) the interlaced configurations of CNC also make it to show higher active sites for MPS activation. Thus, CNC exhibits a significantly stronger activating capability than Co3O4, which is the conventional heterogeneous catalyst for MPS. CNC/MPS also displays a lower activation energy (Ea) for ELZ degradation than literatures, showing advantages of CNC. Mechanisms for MPS activation and ELZ degradation were also elucidated to further understand elimination process of ELZ by MOF-derived cobaltic catalysts. [ABSTRACT FROM AUTHOR]

Commercial zinc metal powder requires activation for consistent and reliable use as a reductant in the formation of organozinc reagents from organohalides, and for the avoidance of supplier and batch‐to‐batch variability. However, the impact of activation methods on the reaction environments of subsequent intermediates has been unknown. Herein, a fluorescence lifetime imaging microscopy (FLIM) method is developed to bridge this knowledge gap, by imaging and examining reaction intermediates on zinc metal that has been activated by pretreatment through different common methods (i. e., by chemical activation with TMSCl, dibromoethane, or HCl; or by mechanical activation). The group of chemical activating agents, previously thought to act similarly by removing oxide layers, are here shown to produce markedly different reaction environments experienced by subsequent oxidative‐addition intermediates from organohalides – data uniquely available through FLIM's ability to detect small quantities of intermediates in situ coupled with its microenvironmental sensitivity. These different microenvironments potentially give rise to different rates of formation, subsequent solubilization, and reactivity, despite the shared "[RZnX]" molecular structure of these intermediates. This information revises models for methods development for oxidative addition to currently sluggish metals beyond zinc by establishing diverse outcomes for pretreatment activation methods that were previously considered similar. [ABSTRACT FROM AUTHOR]

Exploring efficient non-precious metal sulfides as electrocatalysts for the hydrogen evolution reaction (HER) is crucial. Cobalt disulfide (CoS 2) has gained attention for its favorable intrinsic activity, impressive metal conductivity, and cost-effectiveness. However, the weak adsorption of H* at the sulfur (S) sites on the surface of CoS 2 leaves room for enhancing its HER intrinsic activity. Vacancy engineering emerges as a valuable strategy to modulate the local charge density, optimizing hydrogen adsorption free energy and catalytic performance in HER. Taking advantage of plasma technology, known for its rapid and efficient defect creation, we synthesized porous CoS 2 nanowire arrays enriched with S vacancies (V s -CoS 2 /CC) through Ar plasma treatment. Notably, at a current density of 10 mA cm−2, V s -CoS 2 /CC exhibits a lower overpotential (170 mV) compared to pure CoS 2 /CC (236 mV). Furthermore, V s -CoS 2 /CC demonstrates exceptional electrochemical stability. Experimental data and density functional theory calculations jointly reveal that introducing S vacancies reduces local charge density around S atoms, activating inert sulfur sites and enhancing the intrinsic activity of CoS 2 for HER. This study introduces a novel concept of defect-engineered activation in metal compound catalysts, employing a plasma approach to advance HER performance. [Display omitted] • By introducing V s through plasma treatment, V s -CoS 2 /CC is obtained. • V s -CoS 2 /CC exhibits excellent HER catalytic performance. • The introduction of V s activates the inert S sites in CoS 2. [ABSTRACT FROM AUTHOR]

Metal‐based drugs currently dominate the field of chemotherapeutic agents; however, achieving the controlled activation of metal prodrugs remains a substantial challenge. Here, we propose a universal strategy for the radiation‐triggered activation of metal prodrugs via nanosurface energy transfer (NSET). The core–shell nanoplatform (Ru‐GNC) is composed of gold nanoclusters (GNC) and ruthenium (Ru)‐containing organic–inorganic hybrid coatings. Upon X‐ray irradiation, chemotherapeutic Ru (II) complexes were released in a controlled manner through a unique NSET process involving the transfer of photoelectron energy from the radiation‐excited Ru‐GNCs to the Ru‐containing hybrid layer. In contrast to the traditional radiation‐triggered activation of prodrugs, such an NSET‐based system ensures that the reactive species in the tumor microenvironment are present in sufficient quantity and are not easily quenched. Additionally, ultrasmall Ru‐GNCs preferably target mitochondria and profoundly disrupt the respiratory chain upon irradiation, leading to radiosensitization by generating abundant reactive oxygen species. Consequently, Ru‐GNC‐directed radiochemotherapy induces immunogenic cell death, resulting in significant therapeutic outcomes when combined with the programmed cell death‐ligand 1 (PD−L1) checkpoint blockade. This NSET strategy represents a breakthrough in designing radiation‐triggered nanoplatforms for metal‐prodrug‐mediated cancer treatment in an efficient and controllable manner. [ABSTRACT FROM AUTHOR]

Murine norovirus (MNV) undergoes extremely large conformational changes in response to the environment. The T = 3 icosahedral capsid is composed of 180 copies of ~58-kDa VP1 comprised of N-terminus (N), shell (S), and C-terminal protruding (P) domains. At neutral pH, the P domains are loosely tethered to the shell and float ~15 Å above the surface. At low pH or in the presence of bile salts, the P domain drops onto the shell and this movement is accompanied by conformational changes within the P domain that enhance receptor interactions while blocking antibody binding. While previous crystallographic studies identified metal binding sites in the isolated P domain, the ~2.7-Å cryo-electron microscopy structures of MNV in the presence of Mg2+ or Ca2+ presented here show that metal ions can recapitulate the contraction observed at low pH or in the presence of bile. Further, we show that these conformational changes are reversed by dialysis against EDTA. As observed in the P domain crystal structures, metal ions bind to and contract the G’H’ loop. This movement is correlated with the lifting of the C’D’ loop and rotation of the P domain dimers about each other, exposing the bile salt binding pocket. Isothermal titration calorimetry experiments presented here demonstrate that the activation signals (bile salts, low pH, and metal ions) act in a synergistic manner that, individually, all result in the same activated structure. We present a model whereby these reversible conformational changes represent a uniquely dynamic and tissue-specific structural adaptation to the in vivo environment. IMPORTANCE The highly mobile protruding domains on the calicivirus capsids are recognized by cell receptor(s) and antibodies. At neutral pH, they float ~15 Å above the shell but at low pH or in the presence of bile salts, they contract onto the surface. Concomitantly, changes within the P domain block antibody binding while enhancing receptor binding. While we previously demonstrated that metals also block antibody binding, it was unknown whether they might also cause similar conformational changes in the virion. Here, we present the near atomic cryo-electron microscopy structures of infectious murine norovirus (MNV) in the presence of calcium or magnesium ions. The metal ions reversibly induce the same P domain contraction as low pH and bile salts and act in a synergistic manner with the other stimuli. We propose that, unlike most other viruses, MNV facilely changes conformations as a unique means to escape immune surveillance as it moves through various tissues. [ABSTRACT FROM AUTHOR]

The effect of metal nitrates on the activation of anthracite combustion process has been studied. Fe(NO3)2 · 9H2O and Cu(NO3)2 · 3H2O were used as nitrates in an amount of 5 wt% applied to anthracite powder (fraction less than 0.1 mm) by incipient wetness impregnation. Using scanning electron microscopy and EDX mapping, it was found that using this method of applying the additive makes it possible to achieve high dispersion and uniform distribution in the fuel composition. The characteristics of oxidation, ignition, and combustion were studied using thermal analysis methods and high-speed video recording in the combustion chamber at a temperature of 800°C. It was found that the use of metal nitrates contributes to an increase in the reactivity of anthracite as evidenced by a decrease in the temperature of the intensive oxidation beginning (ΔTi) by 23–84°C and the ignition delay time (Δti) by 0.9–2.2 seconds. The greatest effect of changing the reactivity of anthracite was recorded in the case of using copper nitrate additive. The use of nitrates also contributed to the decrease in the resulting fuel underburning (from 3.5 to 0.4 wt%) and gas-phase CO compounds (by 31–53%). At the early stages, combustion process of modified samples was accompanied by periodic formation of micro-explosions, which led to the activation and development of the particle surface. [ABSTRACT FROM AUTHOR]

The activation procedures of metals and alloys, crucial for hydrogen absorption, pose a significant challenge in the large-scale application of metal hydrides. This study introduces, for the first time, the Pulsed Laser Activation (PLA) method for hydrogen storage alloys. We demonstrated that the hydrogen storage ability of an aged (exposed to air for 30 days) Ti 11 V 30 Nb 28 Cr 31 body-centered cubic alloy can be restored by scanning the sample with a nanosecond pulsed laser for only 3 min. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) analyses were conducted to investigate structural features that changed in the Ti 11 V 30 Nb 28 Cr 31 samples after ageing and after the PLA treatment. Surface remelting, the formation of oxide layers, and crack formation appear to be factors influencing the hydrogen storage ability of the Ti 11 V 30 Nb 28 Cr 31 alloy activated via PLA. While the mechanisms involved in the PLA are not clear yet, this procedure paves the way for the development of activation methods based on laser-metal interactions that can be easily applied to metals and alloys for hydrogen storage systems. • The novel Pulsed Laser Activation Method (PLA) is introduced. • PLA is effective to retore the hydrogen storage ability of alloys exposed to air. • The PLA method was tested in the Ti 11 V 30 Nb 28 Cr 31 alloy exposed to air for 30 days. • The changes on the alloy surface caused by the PLA method were investigated. [ABSTRACT FROM AUTHOR]

Dimers and oligomers of alkenes represent a category of compounds that are in great demand in diverse industrial sectors. Among the developing synthetic methods, the catalysis of alkene dimerization and oligomerization using transition metal salts and complexes is of undoubted interest for practical applications. This approach demonstrates substantial potential, offering not only elevated reaction rates but also precise control over the chemo-, regio-, and stereoselectivity of the reactions. In this review, we discuss the data on catalytic systems for alkene dimerization and oligomerization. Our focus lies in the analysis of how the activity and chemoselectivity of these catalytic systems are influenced by various factors, such as the nature of the transition metal, the ligand environment, the activator, and the substrate structure. Notably, this review particularly discusses reaction mechanisms, encompassing metal complex activation, structural and dynamic features, and the reactivity of hydride intermediates, which serve as potential catalytically active centers in alkene dimerization and oligomerization. [ABSTRACT FROM AUTHOR]

A biradical cyclic alkyl(amino)carbene-stabilised 9,10-diboraanthracene (DBA) activates small molecules such as hydrogen, phenyl azide or TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl) across its two boron atoms, while reactions with [(MeCN)3M(CO)3] (M = Cr, Mo, W) yield the first half-sandwich DBA complexes of the form [(η6-DBA)M(CO)3]. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. A strongly metal-support interaction of Cu-SA/CNH catalyst was prepared. • 2. The Cu-SA/CNH with Cu−N 4 coordination was utilized for the photo-Fenton reaction. • 3. The Cu−N 4 facilitated the Cu2+/Cu+ cycle through intermediate state formation. • 4. The affinity of H 2 O 2 to bind with Cu d xz increased nearly 10 times. • 5. The Cu-SA/CNH/PF system achieved an impressive 98.1% degradation efficiency of TC. Single-atom photo-Fenton (PF) reaction is widely employed for the degradation of antibiotics and water disinfection. However, the key fundamental issues of the valence state cycling of single-atom metals and the activation of hydrogen peroxide (H 2 O 2) in the PF process remain indistinct. Herein, we developed a catalyst donated as Cu single atoms anchored hydrangea-like carbon nitride (Cu-SA/CNH) with Cu−N 4 coordination for PF reaction. Compared to pristine CNH, the Cu-SA/CNH exhibited a 2.42-fold increase in PF kinetics. The Cu-SA/CNH/PF system achieved 98.1% degradation efficiency of tetracycline and effectively inactivated Escherichia coli within 30 min. Density functional theory calculations demonstrated that the formation of Cu−N 4 effectively improved the energy of the Cu d orbitals, leading to the generation of intermediate states that facilitated the Cu2+/Cu+ cycle. The adsorption capacity of Cu d xz orbitals on H 2 O 2 increased nearly 10 times. This work provides valuable insights for enhancing single-atom PF activity to address environmental pollution. [ABSTRACT FROM AUTHOR]

Single Atom Catalysts (SACs) are a new frontier in catalysis, merging the positive aspects of both homogeneous and heterogenous catalysts. CO 2 electrochemical reduction is a key reaction for the energy transition. In this work, we investigate the role of the local coordination on the activation of CO 2 on SACs, by means of density functional theory (DFT) calculations. We scrutinize 20 transitional metal atoms embedded in a graphene support. The results indicate that the local coordination has a critical role both to the binding energy of the metal to the support and the activation of CO 2. The role of the environment around the active site is as important as the nature of the metal atom. At the same time, the stability of reaction intermediates strongly depends on the local coordination. In some cases, the relative stability of the intermediates changes as function of the environment, affecting the selectivity of the reaction. This study provides evidence of the importance of the local coordination in single-atom catalysis, a crucial aspect if one is interested in providing a rationale to the reactivity, or in predicting novel catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnFe-LDH-3@CoNC/peroxymonosulfate shows excellent performance for ciprofloxacin removal. • ZnFe-LDH acts as both catalyst and sacrificial agent protecting cobalt active sites from leaching. • SO 4 •−, •OH, O 2 •−and 1O 2 participate in the degradation of ciprofloxacin. • CIP transform pathways and mechanism over ZnFe-LDH-3@CoNC/peroxymonosulfate system are elucidated. ZnFe layered double hydroxide (ZnFe-LDH) wrapped metal–organic framework derived cobalt and nitrogen-doped carbon-based materials (ZnFe-LDH@CoNC) were synthesized. The fabricated nanocomposites exhibited uniform distribution of ZnFe-LDH-3 on CoNC matrix. Degradation efficiency of ciprofloxacin (CIP, 10 mg/L) in the peroxymonosulfate (PMS)-containing catalytic system reached up to 98.5 % at a dosage of 0.2 g/L ZnFe-LDH-3@CoNC and 0.4 g/L PMS at a reaction time of 30 min at 25 °C. The ZnFe-LDH-3@CoNC/PMS catalytic system was found to act as a pH buffer and it exhibited more stable activity in cyclic tests compared with the CoNC/PMS catalytic system. Quenching experiments and EPR analyses showed that 1O 2 was the primary reactive species in the ZnFe-LDH-3@CoNC/PMS catalytic system. Degradation intermediate products of CIP were identified and a potential degradation mechanism was suggested. The ZnFe layered double hydroxide wrapped metal–organic framework advances methods in environmental catalyst design and simultaneously improves active metal for PMS activation. [ABSTRACT FROM AUTHOR]

The first Pd-catalyzed [5 + 2] rollover annulation of 1-benzylpyrazoles has been developed to afford a novel class of 1H-benzo[ e ]furo[3,4- c ]pyrazolo [1,5-a]azepin-3(8H)-one derivatives in good to excellent yields. The reaction proceeds through a sequential ortho -C–H bond rollover annulation followed by lactonization. In this approach, the formation of two C–C bonds is accompanied by lactonization in a single step. [Display omitted] • First report on C–H functionalization of N -benzylpyrazoles with hydroxyalkynoates. • Pd(III)]/Ag(I) catalytic system found to be effective. • A wide substrate scope with high functional group tolerance. • Novel scaffolds for drug discovery. [ABSTRACT FROM AUTHOR]

The improvement in the degradation efficiency of dimethoate was achieved through the activation of UV light and metal ions. The study found that Fe(VI) was effectively activated by Cu(II), Fe(III), and Fe(II), resulting in an improved removal rate of dimethoate in water, with the activation efficiency of Cu(II) > Fe(III) > Fe(II). Under UV irradiation, the synergistic activation effects of UV-Cu(II) and UV-Fe(III) were most pronounced and positively correlated with light intensity. The mineralization rate of dimethoate by UV-Fe(III)-Fe(VI) reached up to 37 %, significantly outperforming the Cu(II)-Fe(VI) system. The main active species in the Cu(II)-Fe(VI) and Fe(III)-Fe(VI) systems were Cu(III) and Fe(IV)/Fe(V), while those in the UV-Fe(III)-Fe(VI) were ·OH and ·O 2 - radicals, respectively. In the UV-metal ions activated Fe (VI) system, the main degradation mechanisms of dimethoate were hydrolysis, cleavage, oxidation, and recombination. The impacts of water quality parameters on degradation efficiency were also investigated, finding that Cl- had almost no effect, while SO 4 2- had a slight repression effect, and HCO 3 -, CO 3 2- and NO 2 - exhibited strong inhibitory effects. Finally, the promising application of the UV-metal ion-Fe(VI) system in actual water environments was proposed, achieving effective removal with minimal environmental risks. [Display omitted] • Fe(VI) can slightly degrade dimethoate, and metal ion activation intensifies this. • Different metal ions vary in activation ability: Cu(II) > Fe(III) > Fe(II). • UV enhances Cu(II) and Fe(III) activation of Fe(VI) for dimethoate degradation. • The introduction of UV light changes the active material. • The UV-Fe(III)-Fe(VI) system may lead to more complete degradation of dimethoate. [ABSTRACT FROM AUTHOR]

Polyaromatic hydrocarbons (PAHs) are the most persistent compounds that get contaminated in the soil and water. Nearly 16 PAHs was considered to be a very toxic according US protection Agency. Though its concentration level is low in the environments but the effects due to it, is enormous. Advanced Oxidation Process (AOP) is an emergent methodology towards treating such pollutants with low and high molecular weight of complex substances. In this study, sulfate radical (SO 4 ‾•) based AOP is emphasized for purging PAH from different sources. This review essentially concentrated on the mechanism of SO 4 ‾• for the remediation of pollutants from different sources and the effects caused due to these pollutants in the environment was reduced by this mechanism is revealed in this review. It also talks about the SO 4 ‾• precursors like Peroxymonosulfate (PMS) and Persulfate (PS) and their active participation in treating the different sources of toxic pollutants. Though PS and PMS is used for removing different contaminants, the degradation of PAH due to SO 4 ‾• was presented particularly. The hydroxyl radical ( • OH) mechanism-based methods are also emphasized in this review along with their limitations. In addition to that, different activation methods of PS and PMS were discussed which highlighted the performance of transition metals in activation. Also this review opened up about the degradation efficiency of contaminants, which was mostly higher than 90% where transition metals were used for activation. Especially, on usage of nanoparticles even 100% of degradation could be able to achieve was clearly showed in this literature study. This study mainly proposed the treatment of PAH present in the soil and water using SO 4 ‾• with different activation methodologies. Particularly, it emphasized about the importance of treating the PAH to overcome the risk associated with the environment and humans due to its contamination. [ABSTRACT FROM AUTHOR]

• Porous Zn3Mo2O9 microflowers assembled with cross-linked nanosheets are synthesized using a facile hydrothermal method combined with calcination. • Porous flower-like microstructures are constructed by numerous cross-linked nanosheets as building blocks. • Gas sensor based on porous Zn3Mo2O9 microflowers exhibits good sensing performances for volatile organic gases (VOCs), especially for the high selectivity of ethanol gas. • The larger available surface area, favorable hierarchical flower-like microstructure assembled by cross-linked nanosheets, larger pore size, and higher relative percentage of the OC and OV, and oxidative catalytic activation of metal elements all jointly contribute to superior sensing performances. Porous Zn 3 Mo 2 O 9 microflowers assembled with cross-linked nanosheets were synthesized using a facile hydrothermal method combined with calcination. Compared to pure MoO 3 nanorod sensor, the Zn 3 Mo 2 O 9 sensor exhibited a stronger response of 58.3 toward 100 ppm ethanol at 220 °C, with a shorter response/recovery times (10 s/14 s). The excellent stability and repeatability of the Zn 3 Mo 2 O 9 sensors were also demonstrated. The detected limit for the ethanol vapor was as low as 29 ppb. The superior ethanol sensing properties were attributed to favorable porous microflowers assembled by cross-linked nanosheets, higher porosity, large specific surface area, higher relative percentage of the O C and O V , and oxidative catalytic activation. This was advantageous for providing abundant surface active sites for the adsorption of gas molecules, as well as accelerating the oxidation of more ethanol molecules between oxygen species and ethanol gas. This study provides practical application for detecting alcohol gases. Porous flower-like Zn 3 Mo 2 O 9 microstructures consisting of uniform cross-linked nanosheets were synthesized using a facile hydrothermal method combined with calcination. The porous Zn 3 Mo 2 O 9 microflowers sensors presented a higher response (58.3), shorter response–recovery times (10 s/14 s), and lower working temperature (220 °C) for 100 ppm ethanol gas. The Zn 3 Mo 2 O 9 microflowers sensors also showed good responses toward other alcohol gases such as isopropanol, and methanol. The superior ethanol sensing properties were attributed to favorable porous microflowers assembled by cross-linked nanosheets, higher porosity, larger specific surface area, higher relative percentage of the O C and O V , and oxidative catalytic activation. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Figures of merit of light-activated gas sensors, operable at room temperature are addressed. • Role of light irradiation on the sensing material to elevate gas-sensing performances has been discussed. • 2-D material-based gas sensor shows significant response under visible light activation. • Discussed the future scopes towards the development of light-activated gas sensors. In this modern era, the necessity of a safe environment with a swift detection of even minute concentrations of hazardous and combustible gases has spurred significance in the advancement of gas sensor technology. In this aspect, the room temperature operable gas sensors have marked their importance by ensuring the safe detection of combustible gases. Nonetheless, the incomplete recovery of such gas sensors requires thermal activation, which entails several limitations. Therefore, the light-activation of gas sensors has garnered considerable attention owing to its compactness and cost-effective operations. The light-activation generates the electron-hole pairs which activate the sensing surface and modulate the charge carrier concentration, thereby enhancing the gas-sensing performances. In this review, the gas-sensing performances of various photoactive sensing materials including metal oxides and two-dimensional materials under light irradiation have been discussed. The gas sensors based on metal oxide and two-dimensional materials have shown significant performance in terms of response, as well as sharp response and recovery times under both ultra-violet and visible light illumination. Finally, this review emphasizes the challenges and future scopes associated with the light-activated room temperature operable gas sensors, which could lead a pathway toward the development of an ultrafast gas sensor. [ABSTRACT FROM AUTHOR]

A novel type of NiFe 2 O 4 @CuO composites with core–shell structure was prepared by hydrothermal-freeze-drying-synchronous pyrolysis and coupled with ultrasound to degrade OTC via activated PS. The degradation performance was improved due to the cavitation effect of ultrasound and the synergistic interaction between the 15-NFO@CuO surface metals that promoted PS activation. In addition, the degradation pathways and intermediates of OTC were proposed based on LC-MS and 3D-EEM analysis. [Display omitted] • NiFe 2 O 4 particles attached to octahedral CuO to form magnetic core–shell structural complexes. • Dual active components and a multi-stage pore structure are designed. • The activation of PS by the cavitation effect of ultrasound and the synergistic interaction between 15-NFO@CuO surface metals are facilitated. Coupled advanced oxidation processes (AOPs) based on ultrasound and transition metal-activated persulfate (PS) have attracted considerable attention for the degradation of antibiotics. NiFe 2 O 4 @CuO composites with core–shell structure were prepared by hydrothermal-freeze-drying-synchronous pyrolysis and coupled with ultrasound to degrade oxytetracycline (OTC) via activated PS. The coupled oxidation process (15-NFO@CuO/US/PS) can substantially enhance the degradation rate of OTC due to the synergistic effects from both ultrasonic and metal activation. X-ray photoelectron spectroscopy reflects that the synergistic interaction between the metals on the 15-NFO@CuO surface can effectively enhance the redox cycling process of metal ions and promote PS activation. Free radical quenching experiments and electron paramagnetic resonance spectroscopy (EPR) identified and confirmed the presence of sulfate radicals (SO 4 •−), hydroxyl radicals (•OH), and superoxide radicals (O 2 •−). In addition, the degradation pathways and intermediates of OTC were proposed based on liquid chromatography-mass spectrometry (LC-MS) and three-dimensional excitation-emission matrix (3D-EEM) analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The activation mechanism of sphalerite by impurities with d10 electron configuration is studied. • The relationship between d-s orbital hybridization and metal ion activated sphalerite is revealed. • The greater the polarizability, the better the activation of sphalerite by metal ions. The activation mechanism of metal ions with d10 inert electronic configurations on sphalerite (ZnS) were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and X-ray photoelectron spectroscopy (XPS), combined with density functional theory (DFT). Flotation experiments showed that the addition of activators increased sphalerite recovery by 50–70 %. The XPS results indicated that these inert cations with d10 electronic configurations formed stable metal sulfides (Cu 2 S, CuS, Ag 2 S, CdS, and HgS) on the sphalerite surface. The FTIR results demonstrated that the activated sphalerite enhanced the adsorption stability of butyl xanthate on the sphalerite surface. DFT studies found that metal ion introduction reduced surface relaxation and decreased the band gap on the sphalerite surface, both of which increased butyl xanthate adsorption. Finally, it was suggested in this study that the energy required for the d10 to d9s1 electron transition and the polarization could be used to predict the potential sphalerite activator. [ABSTRACT FROM AUTHOR]

Inadequate limit of detection at room temperature and unsatisfactory selectivity remain challenge for wide applications of the chemiresistive gas sensors. Nanostructured gas sensors ensure the desirable activation energy for the gas adsorption and chemical reactions, favorable for room-temperature parts-per-billion (ppb) level gas detection. In this work, we demonstrated a single-chip integrated gas sensor array (4 ×4 pixels) based on kinds of metal (Pt, Pd, Au, Ag) decorated 3D SnO 2 nanotubes for ultrasensitive room-temperature gas-sensing. The nanostructured sensor array has a high surface area-to-volume ratio, enabling room temperature sensing with high detection response toward H 2 (minimum 5 ppm), formaldehyde (minimum 50 ppb), toluene (minimum 50 ppb) and NO 2 (minimum 100 ppb) with the detection accuracy within 5% range, respectively. In addition, the effect of metals decoration on the gas identification features were systematically conducted, and these specific response features can be mainly attributed to metal activation capability toward the gases, which enables demonstrating differentiable response patterns for the target gases identification employing a pattern recognition algorithm. These results demonstrate that the proposed strategy helps to provide an excellent route for the future low-power-consumption smart sensing devices design and fabrication. • Metal-decorated 3D tin oxide nanotubes sensor array chip was realized. • The sensor array enables room temperature gas sensing with high detection accuracy. • The sensor array enables achieving gas identification in the specific circumstances. [ABSTRACT FROM AUTHOR]

A recent article in Angewandte Chemie International Edition discusses a new approach to cancer chemotherapy using radiation-triggered metal prodrug activation. The researchers, Fangman Chen, Wen Sun, Dan Shao, and their colleagues, developed a strategy called nanosurface energy transfer to overcome the limitations of current methods. This technique showed promising results in combined cancer treatment. The article provides valuable insights for library patrons researching cancer treatment options. [Extracted from the article]

A recent article in Angewandte Chemie discusses a new approach to cancer chemotherapy using radiation-triggered metal prodrug activation. The researchers, including Fangman Chen, Wen Sun, and Dan Shao, developed a strategy called nanosurface energy transfer to overcome the limitations of current methods. This technique showed promising results in combined cancer treatment. The article provides valuable insights for library patrons researching cancer treatment options. [Extracted from the article]

[Display omitted] • The formation of metallic clusters in MM'AlPO-5 is thermodynamically favored. • No NH 3 activation was found in TiAPO-5 and ZrAPO-5. • CoZrAPO-5 seems to be the more active for the NH 3 activation than CoTiAPO-5. • N H bond breaking is aided by the bridging oxygen atom of the M O M' bond. ONIOM-DFT calculations have been carried out in order to determine how the neighboring metal influences the activation free energies (ΔG≠) and the mechanisms of NH 3 activation in a series of mono and disubstituted aluminophosphates MM'APO-5, (M, M' = Co, Ti Zr). The results revealed that metal clustering is thermodynamically favorable (ΔG < 0) for all MAPO-5s and MM'APO-5s studied here. The aluminophosphates TiAPO-5 and ZrAPO-5 are unable to activate NH 3 due to their inability to stabilize the key intermediate M NH 2. The calculated activation free energy values (ΔG≠) suggest that CoZrAPO-5 is better suited for NH 3 activation, as its values are lower than those of CoTiAPO-5 in the mechanism studied. [ABSTRACT FROM AUTHOR]