Publications by authors named "Xiwen Du"

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.

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  • * A new strategy is introduced to create oxygen-deficient Ni-Mo-Fe structures in NiFe (oxy)hydroxide that improve reaction kinetics by lowering energy barriers in key steps of the HER.
  • * The enhanced catalyst, NFM-OV/NF, shows exceptional performance with low overpotentials and impressive long-term stability, making it a cost-effective option for producing hydrogen, achieving a price of $0.92 per gallon equivalent, which is below 2026 energy targets.
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  • HO splitting is essential for electrocatalytic hydrogenation reactions, as it generates surface hydrogen species (*H) which can lead to inefficient reactions due to poor matching with reactants.
  • A Cu-Ag alloy with a staggered superlattice structure has been developed to improve the HO splitting process through a hydrogen transfer reaction (HTR) within the water layer, enhancing the formation and utilization of *H.
  • This new HTR pathway significantly boosts acetylene hydrogenation efficiency, achieving 91.2% Faradaic efficiency at 0.38 A/cm, compared to traditional methods without the superlattice structure.
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  • A molecular modification strategy shows promise for improving the efficiency of CO electroreduction reactions.
  • Researchers used DFT (Density Functional Theory) calculations to analyze how glycine modification affects the process on copper surfaces.
  • The study found that the modified glycine influences the interaction with reaction intermediates, which alters the energy required for CO electroreduction.
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  • Cost-effective transition metal chalcogenides like CoSe have potential as electrocatalysts for hydrogen evolution reactions but struggle with HER kinetics and stability.
  • A new catalyst, (c/o)-CoSe-W, features a nanoflower shape and W doping, which allows a controlled phase transition that enhances its performance.
  • This catalyst achieves exceptional HER activity similar to platinum, with low overpotentials in both alkaline (29.8 mV) and acidic (35.9 mV) environments, while also demonstrating long-term durability thanks to its unique phase interfaces.
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As 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.

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Developing 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.

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  • Researchers developed a highly effective electrode for hydrogen production that can operate under extreme current densities, addressing the need for efficient hydrogen evolution reactions (HER).
  • The electrode, made from Ag(S)@NiO on nickel foam, benefits from a unique laser technique that enhances the bonding between materials, improving their overall performance and durability.
  • This innovative design achieved a remarkably low HER overpotential and maintained activity even after long testing periods, outperforming many existing non-platinum catalysts.
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A 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.

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Hydrogen 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.

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Single-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.

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  • Free energy calculation of small molecules or ions in water is crucial for electrochemistry, but traditional methods often have limitations due to their reliance on complex ab initio approaches.
  • The authors developed a hybrid method combining ab initio molecular dynamics (AIMD) with an implicit solvent model, utilizing a small water cluster around the ion to accurately compute ion solvation energy.
  • Their results show excellent agreement with experimental data for solvation voltages and energies, and they also obtained important hydration properties like radial pair distribution functions, while highlighting some remaining challenges with their method.
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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.

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The 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.

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  • Metallic materials with special surface structures are in demand due to their unique properties, but creating bulk materials with specific crystal faces at the nanoscale is challenging.
  • The study presents a new method that combines ion implantation and oxidation-etching to modify the surface of a copper plate, exposing Cu(100) crystal planes.
  • The resulting Cu plate shows improved catalytic performance in hydrogen evolution reactions, requiring only 273 mV to achieve a current density of 10 mA/cm, indicating better efficiency due to its unique surface structure.
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The 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.

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A 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).

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  • - The text discusses the development of a highly active copper catalyst for the hydrogen evolution reaction (HER) by using friction stir welding (FSW), which creates high-energy surfaces.
  • - FSW effectively mixes iron and copper, leading to a transformation of iron phases that facilitates the growth of energy-efficient copper planes, enhancing the catalyst's performance compared to platinum.
  • - The study highlights that the high-energy surface structure allows better adsorption of hydrogen, improving HER efficiency, and positions FSW as a cost-effective method for large-scale catalyst production.
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As 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.

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The 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.

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Moxifloxacin 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.

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In 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.

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Engineering 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.

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Purpose: 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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