The Preparation Of Two-dimensional Ni-based Nanomaterials And The Study On The Property Of Water Splitting

The core reaction of water electrolysis is oxygen evolution reaction(OER)which produces hydrogen.However,it seriously affects the development of water splitting because of its complicated four-electron transfer process.As a consequence,it is very urgent to speed up the process of efficient catalysts'research and development in order to improve the efficiency of OER.At present,Pt is the represent of the noble metal catalyst because of its high activity among the electrode materials.However,it doesn't have the ability to be widely used in water splitting and fuel cell on account of high price,scarce reserves,poor poison resistance and easy deactivation.From what has been discussed above,the development of non-noble metal catalysts with high performance,low cost and good stability are the focus of current work.Firstly,Ni(OH)₂ nanosheets grown on the Ni foam substrate has been synthesized by hydrothermal method.The final rich fold Ni₃S₂ nanosheets has been prepared successfully by sulfide the precursor Ni(OH)₂ and this section adopted the same hydrothermal method.The activity of the dynamic self-optimizing(DSO)25 h-Ni₃S₂-NF for oxygen evolution is significantly enhanced compared with that of initial 0 h-Ni₃S₂-NF and the precursor catalyst in electrochemical performance testing,which required merely 241 m V overpotential to deliver a current density of 20 m A cm^-2,and its shows low Tafel slope(?40 m V dec^-1),showing that the DSO process may have active effect on OER process.From the study of DSO process,we found that the DSO catalyst's surface was no longer composed of a single Ni₃S₂,but a layer of nickel oxide.The unique rich folding nanostructure of Ni₃S₂ and the synergistic effect of self-optimized Ni O_xand Ni₃S₂ both promoted the performance of OER.In order to ensure the stability of the catalyst,we conducted 60 h stability test and the result indicated the good stability.At the same time,we also investigated the effect of added materials on morphology and crystal phase.