Machine Learning-Assisted Low-Dimensional Electrocatalysts Design for Hydrogen Evolution Reaction

Efficient electrocatalysts are crucial for hydrogen generation from electrolyzing water.Nevertheless,the conventional"trial and error"method for producing advanced electrocatalysts is not only cost-ineffective but also time-consuming and labor-intensive.Fortunately,the advancement of machine learning brings new opportunities for electrocatalysts discovery and design.By analyzing experimental and theoretical data,machine learning can effectively predict their hydrogen evolution reaction(HER)performance.This review summarizes recent developments in machine learning for low-dimensional electrocatalysts,including zero-dimension nanoparticles and nanoclusters,one-dimensional nanotubes and nanowires,two-dimensional nanosheets,as well as other electrocatalysts.In particular,the effects of descriptors and algorithms on screening low-dimensional electrocatalysts and investigating their HER performance are highlighted.Finally,the future directions and perspectives for machine learning in electrocatalysis are discussed,emphasizing the potential for machine learning to accelerate electrocatalyst discovery,optimize their performance,and provide new insights into electrocatalytic mechanisms.Overall,this work offers an in-depth understanding of the current state of machine learning in electrocatalysis and its potential for future research.

Oxidation behavior of Mo-Si-B alloys at medium-to-high temperatures

Continuous exploration of high-temperature structural materials is being driven by the needs of gasturbine engines capable of withstanding the high-temperature environment.Relatively low melting points of currently applied superalloys restrain the further improvement of service tempe ratures.With higher melting tempe ratures above 2000℃,Mo-Si-B alloys are regarded as a new generation of ultrahightemperature structural materials.However,oxidation is a concern for the industrial application of Mo-Si-B alloys.Therefore,an in-depth understanding of the oxidation mechanisms may contribute to solving this issue,whereas relevant reviews about their recent advances are lacking.In the current work,a comprehensively systematic review about the oxidation behaviors of Mo-Si-B alloys is described for this purpose.

Heat treatment-induced Co^(3+) enrichment in CoFePBA to enhance OER electrocatalytic performance

Increasing active metal sites is a valid approach to improve the catalytic activity of the catalyst. Co^(3+) is the main active metal site of Co-based catalysts. In this research work, through the partial transformation of CoFePBA (CFP) via low-temperature heat treatment, the effective control of the Co^(3+)/Co^(2+) ratio has been achieved. The partial transformation strategy of low-temperature heat treatment can not only maintain the original framework structure of CFP, but also increase more active sites. The characterization results show that the CFP-200 sample obtained via heat treatment at 200 ℃ for 2 h under N2 atmosphere has the highest Co^(3+)/Co^(2+) ratio. As an oxygen evolution reaction electrocatalyst, CFP-200 shows the best electrocatalytic activity among all samples. In 1.0 mol/L KOH electrolyte, the overpotential is 312 mV at a current density of 10 mA/cm2. Therefore, low-temperature heat treatment provides an effective method for preparing low-cost and high-efficiency electrocatalysts.

Recent advances of vanadium-based cathode materials for zinc-ion batteries

Zn-ion batteries(ZIBs) have gained great attention as promising next-generation power sources, because of their low cost, enviable safety and high theoretical capacity. Recently, massive researches have been devoted to vanadium-based materials as cathodes in ZIBs, owing to their multiple valence states, competitive gravimetric energy density, but the capacity degradation, sluggish kinetics, low operating voltage hinder further optimization of their performance in ZIBs. This review summarizes recent progress to increase the interlayer spacing, structural stability, and the diffusion ability of the guest Zn ions, including the insertion of different ions, introduction of defects, design of diverse morphologies, the combination of other materials. We also focus on approaches to promoting the valuable performance of vanadiumbased cathodes, along with the related ongoing scientific challenges and limitations. Finally, the future perspectives and research directions of vanadium-based aqueous ZIBs are provided.

Shining light on transition metal tungstate-based nanomaterials for electrochemical applications:Structures,progress,and perspectives

Transition metal tungstate-based nanomaterials have become one of the research hotspots in electrochemistry due to their abundant natural resources,low costs,and environmental friendliness.Extensive studies have demonstrated their significant potentials for electrochemical applications,such as supercapacitors,Li-ion batteries,Na-ion batteries,electrochemical sensing,and electrocatalysis.Considering the rapidly growing research enthusiasm for this topic over the last several years,herein,a critical review of recent progress on the application of transition metal tungstates and their composites for electrochemical applications is summarized.The relationships between synthetic methods,nano/micro structures and electrochemical properties are systematically discussed.Finally,their promising prospects for future development are also proposed.It is anticipated that this review will inspire ongoing interest in rational designing and fabricating novel transition metal tungstate-based nanomaterials for high-performance electrochemical devices.