沉积电压对Ni-Fe-Sn镀层组织结构及析氢性能的影响

Effects of deposition potential on microstructure and electrocatalytic hydrogen evolution performance of Ni-Fe-Sn films

氢能是一种清洁高效的可再生能源,通过电解水技术低成本、高效率地制备氢气,是当前国际科研的热点之一.发展高性能、低成本、高活性的析氢催化剂是电解水技术目前面临的主要挑战.文中采用恒电位电沉积法在泡沫镍表面合成了菜花状结构的Ni-Fe-Sn镀层.研究了不同沉积电位对镀层的物相、形貌及析氢性能的影响规律.结果表明:随着沉积电位的减少,Ni-Fe-Sn镀层表面逐渐生成了菜花状结构,镀层中Sn含量逐渐增加,而Fe含量则逐渐减少.当沉积电位为-0.9 V时,Ni-Fe-Sn镀层获得最佳的析氢性能,其在10 mA·cm^(-2)电流密度时的析氢过电位仅为62 mV.同时,该镀层表现出良好的电化学稳定性.Ni-Fe-Sn镀层优良的析氢性能归因于菜花状结构提供了较大的电化学活性面积,能够提供更多的反应活性位点;同时适量的Sn和Fe含量减小电荷转移电阻,加快电荷转移速率,增强了镀层的析氢性能.

Hydrogen energy is a clean and efficient renewable energy source,and the preparation of hydrogen by electrolytic water technology with low cost and high efficiency is one of the current hot spots of international scientific research.The development of high-performance,low-cost and high-activity catalysts for hydrogen evolution reaction(HER)is the main challenge in this field.In this study,the cauliflower-like structure Ni-Fe-Sn film on nickel foam is fabricated through one-step potentiostatic electrodeposition route.The effects of deposition potentials on the phase,morphology and HER property of the Ni-Fe-Sn films were studied.The experimental results show that with the decrease of deposition voltage,the cauliflower structure is gradually formed on the surface of Ni-Fe-Sn coating,and the content of Sn increases gradually,while the content of Fe decreases gradually.When the deposition potential is-0.9 V,the Ni-Fe-Sn coating has the best HER property with the HER overpotential of the Ni-Fe-Sn film being only 62 mV at the current density of 10 mA·cm^(-2).At the same time,the film showed good electrochemical stability.The excellent HER performance of Ni-Fe-Sn film is attributed to the large electrochemical active area provided by the cauliflower structure,which can provide more reactive sites.Meanwhile,the appropriate amount of Sn and Fe decreases the charge transfer resistance,accelerates the charge transfer rate,thus enhances the HER performance of the Ni-Fe-Sn film.