The interaction of defects has been proven effective in regulating the mechanical properties of structural materials, while its influence on the physicochemical performance of functional materials has been rarely reported. Herein, we synthesized Ag nanorods with dense stacking faults and investigated how the defect interaction affects the catalytic properties. We found that the stacking faults can couple with each other to form a unique structure of opposite atoms with extortionately high tensile strain.
View Article and Find Full Text PDFAs promising oxygen evolution reaction (OER) catalysts, spinel-type oxides face the bottleneck of weak adsorption for oxygen-containing intermediates, so it is challenging to make a further breakthrough in remarkably lowering the OER overpotential. In this study, a novel strategy is proposed to substantially enhance the OER activity of spinel oxides based on amorphous/crystalline phases mixed spinel FeNiO nanosheets array, enriched with oxygen vacancies, in situ grown on a nickel foam (NF). This unique architecture is achieved through a one-step millisecond laser direct writing method.
View Article and Find Full Text PDFDeveloping efficient and stable electrocatalysts at affordable costs is very important for large-scale production of green hydrogen. In this study, unique amphoteric metallic element-doped NiFe-LDH nanosheet arrays (NiFeCd-LDH, NiFeZn-LDH and NiFeAl-LDH) using as high-performance bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were reported, by tuning electronic structure and vacancy engineering. It was found that NiFeCd-LDH possesses the lowest overpotentials of 85 mV and 240 mV (at 10 mA cm) for HER and OER, respectively.
View Article and Find Full Text PDFA zinc-infiltration process was adopted to prepare silver-doped copper nanosheet arrays. The larger atomic radius of Ag introduces tensile stress, which lowers the electron density at the s-orbitals of Cu atoms and improves the adsorption capability for hydrogen atoms. As a catalyst for hydrogen evolution, these silver doped copper nanosheet arrays achieved a low overpotential of 103 mV at 10 mA cm in 1 M KOH, which is 604 mV lower than that of pure copper foil.
View Article and Find Full Text PDFHydrogen peroxide (HO) is a powerful industrial oxidant and potential carbon-neutral liquid energy carrier. Sunlight-driven synthesis of HO from the most earth-abundant O and seawater is highly desirable. However, the solar-to-chemical efficiency of HO synthesis in particulate photocatalysis systems is low.
View Article and Find Full Text PDFSingle-crystal planes are ideal platforms for catalytic research. In this work, rolled copper foils with predominantly (220) planes were used as the starting material. By using temperature gradient annealing, which caused grain recrystallization in the foils, they were transformed to those with (200) planes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2022
The electrocatalytic nitrogen oxidation reaction (NOR) to generate nitrate is gaining increasing attention as an alternative approach to the conventional industrial manufacture. But, current progress in NOR is limited by the difficulties in activation and conversion of the strong N≡N bond (941 kJ mol ). Herein, we designed to utilize sulfate to enhance NOR performance over an Rh electrocatalyst.
View Article and Find Full Text PDFThe work function can serve as a characteristic quantity to evaluate the catalytic activity due to its relationship with the surface structure of a material. However, what factors determine the influence of the work function on the electrochemical performance are still unclear. Herein, we elucidate the effect of the work function of Ag on the electrochemical reduction of CO to CO by controlling the ratio of exposed crystalline planes.
View Article and Find Full Text PDFThe valance of Mo is critical for FeMo cofactor in ambient ammonia synthesis. However, the valence effect of Mo has not been well studied in heterogeneous nanoparticle catalysts for electrochemical nitrogen reduction reaction (NRR) due to the dissolution of Mo as MoO in alkaline electrolytes. Here, a MoO catalyst enriched with surface Mo is reported.
View Article and Find Full Text PDFA self-supported silver electrode was prepared by plasma spraying and used for catalysing the hydrogen evolution reaction. Thanks to the non-equilibrium synthetic conditions, the silver catalyst exposes high-energy (200) crystal planes, which enhance the adsorption of hydrogen and improve the intrinsic catalytic activity. As a result, the silver catalyst delivers an overpotential of 349 mV at 10 mA cm, which was much lower than those of Ag foil (742 mV) and commercial Ag powder (657 mV).
View Article and Find Full Text PDFAs a metal-free photocatalyst, graphitic carbon nitride (g-CN) shows great potential for photocatalytic water splitting, although its performance is significantly limited by structural defects due to incomplete polymerization. In the present work, we successfully synthesize highly conjugated g-CN nanofoam through an iodide substitution technique. The product possesses a high polymerization degree, low defect density, and large specific surface area; as a result, it achieves a hydrogen evolution rate of 9.
View Article and Find Full Text PDFThe surface of an electrocatalyst undergoes dynamic chemical and structural transformations under electrochemical operating conditions. There is a dynamic exchange of metal cations between the electrocatalyst and electrolyte. Understanding how iron in the electrolyte gets incorporated in the nickel hydroxide electrocatalyst is critical for pinpointing the roles of Fe during water oxidation.
View Article and Find Full Text PDFMoxifloxacin and levofloxacin are currently recommended as empirical initial treatment options for community-acquired pneumonia (CAP) in China by clinical guidelines and widely used in clinical settings. Several clinical outcomes comparing the efficacy and safety profiles of moxifloxacin versus levofloxacin through a meta-analysis were reported in paper 'Clinical benefits and cost-effectiveness of moxifloxacin as initial treatment for community-acquired pneumonia: a meta-analysis and economic evaluation'. In this dataset, we aimed at investigating more clinical endpoints comparing the efficacy and safety of moxifloxacin and levofloxacin in the treatment of CAP.
View Article and Find Full Text PDFIn this study, a core-shell structure (Ag@Co3O4) was constructed to modify the valence state of cobalt cations precisely by continuously adjusting the shell thickness. There exists a volcano relationship between the valence state of Co sites and OER activity, and the lowest overpotential (212 mV@10 mA cm-2) has been obtained.
View Article and Find Full Text PDFEngineering high-performance electrocatalysts is of great importance for energy conversion and storage. As an efficient strategy, element doping has long been adopted to improve catalytic activity, however, it has not been clarified how the valence state of dopant affects the catalytic mechanism and properties. Herein, it is reported that the valence state of a doping element plays a crucial role in improving catalytic performance.
View Article and Find Full Text PDFPurpose: Moxifloxacin and levofloxacin are currently recommended as empirical initial treatment options for community-acquired pneumonia (CAP) in China according to guidelines. Most studies that evaluated the efficacy and safety of moxifloxacin and levofloxacin in treating CAP as initial empirical treatment were single-centered trials assessing different clinical end points. In addition, there is limited research investigating moxifloxacin's clinical benefits in the context of health care resource utilization and reimbursement from the payer's perspective in China.
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