The development of a hydrogen evolution catalyst with both catalytic activity and stability is critical for hydrogen production from electrolytic water. Herein, a V-based porous alloy was prepared via high-energy ball milling and solid-state sintering. Then, the V-based porous alloy was modified with a Ni-Cu-Mo ternary alloy coating by direct current electrodeposition to obtain a composite hydrogen evolution cathode with high hydrogen evolution activity. The substrate has a certain hydrogen storage capacity combined with a high-activity Ni-Cu-Mo coating. The composite hydrogen evolution cathode exhibited high electrocatalytic activity toward the HER. It can afford a lower overpotential of 93 mV and a smaller Tafel slope of 97.4 mV/dec with a current density of 10 mA/cm 2 in 1.0 M KOH. The composite hydrogen evolution cathode demonstrated outstanding stability after 2000 cycles and good durability after intermittent electrolysis for 20 h. Hydrogen protons can protect the components of the cathode composite from dissolution during discontinuous constant potential electrolysis. The composite hydrogen evolution cathode also exhibited a strong catalytic capacity for hydrogen evolution during intermittent electrolysis under alkaline conditions.
Kai Li,Zijian Hu,Wenxin Yang,Wei Duan,Xiaonan Ni,Zhenjie Hu,Wentao He,Zhicheng Cai,Yike Liu,Zhe Zhao,Xin Deng,Jinyang Liu,Zhi Qu,Feng Jin
Defects, such as pores, microcracks, and thermal damage, pose significant challenges in the selective laser melting (SLM) process of diamond reinforced metal matrix composites. To address these issues, this study utilizes Mo-coated diamond particles prepared via salt bath plating for SLM processing of CoCr-diamond composites. The SLM process parameters including laser power, scanning speed, and hatch spacing were systematically optimized using the response surface method (RSM). Subsequently, the microstructure and mechanical properties of the SLMed CoCr-diamond composites were thoroughly investigated. Notably, a protective layer of Mo 2 C is formed on the surface of diamond particles during the salt bath plating process. When compared to the SLMed CoCr-15 vol% Mo-uncoated diamond composite, the Mo coating significantly enhances the compressive strength by 69 % and flexural strength by an impressive 345 % for the CoCr-15 vol% Mo-coated diamond composite.