Preparation And Electrocatalytic Performance Of Ni（OH）₂/ZrO₂ Heterostructure Bifunctional Catalyst

With the emergence of the global energy crisis and environmental degradation,the development of scientific,efficient,green and sustainable energy has become the focus of research work in countries around the world.As an energy storage and conversion device,fuel cells have become a hot spot in scientific research.At the same time,hydrogen energy has attracted widespread attention due to its clean,efficient,environmentally friendly,and widely distributed resources.The use of hydrogen in fuel cells to convert into electrical energy is a method of killing two birds with one stone.Therefore,researchers are now committed to solving the key reactions of fuel cells and electrolyzed water for hydrogen production,namely oxygen reduction reaction（Oxygen reduction reaction,ORR）and oxygen evolution reaction（Oxygen evolution reaction,OER）.However,finding non-precious metal catalysts that can replace precious metal catalysts is still a huge challenge.In this paper,a simple alcohol-thermal method was used to synthesize a heterostructure Ni（OH）₂/ZrO₂ catalyst in one step.First,a series of characterization methods were used to characterize the morphology and structure of the catalyst.The results showed that the catalyst prepared in this paper had a heterogeneous structure Ni（OH）₂/ZrO₂ catalyst,it is also found that ZrO₂ has a great influence on Ni（OH）₂ through its abundant oxygen vacancies,making Ni（OH）₂/ZrO₂ also show obvious characteristic peaks of surface oxygen vacancies.This may have a certain impact on the electrocatalytic performance of the Ni（OH）₂/ZrO₂heterostructure catalyst.Then,the electrochemical test method was used to characterize the electrocatalytic performance of the catalyst in ORR and OER.The results showed that the heterostructure Ni（OH）₂/ZrO₂ catalyst has excellent ORR and OER performance,this powerful electrocatalytic performance is attributed to the influence of ZrO₂ on Ni（OH）₂through its abundant oxygen vacancies,which inhibits the oxidation of Ni²⁺,stabilizes O*free radicals,and promotes the four-electron transfer process of Ni（OH）₂/ZrO₂.At the same time,the heterogeneous interface between Ni（OH）₂ and ZrO₂ also plays a key role in generating ultra-high activity.Finally,through density functional theory（DFT）calculations to verify the results obtained from the electrochemical test,the results show that the super electrocatalytic performance of the heterostructure Ni（OH）₂/ZrO₂ is not only due to the simultaneous adjustment of the composition and geometric structure,It is also attributed to the abnormal synergistic effect of charge transfer and the heterostructure interface.At the same time,ZrO₂ inhibits the oxidation of Ni²⁺and stabilizes O radicals,this effect is beneficial to promote ORR and OER of the Ni（OH）₂/ZrO₂ heterostructure catalyst,and improves the electrocatalytic performance.