| Water decomposition electrolyzers can convert electricity into storable hydrogen,which is a fascinating and scalable renewable energy conversion technology.In order to accelerate slow hydrogen and oxygen evolution reactions(HER and OER),electrocatalysts are crucial for reducing their kinetic energy potential barriers and ultimately improving energy conversion efficiency.Ni3S2 has an anorthite structure.Due to its inherent Ni-Ni metal network and its conductivity close to metal,it has attracted great attention in the application of electrocatalytic OER.However,the hydrolysis performance of Ni3S2 does not reach the level of commercial application.Therefore,the adjustment of the binding capacity of water splitting intermediates on the surface of Ni3S2 electrocatalyst through substrate effect and interface effect has attracted more and more attention.By systematically studying the OER performance of non-metallic doped Ni3S2,a more stable and efficient electrocatalyst has been found.We have discussed in depth the correlation between the electronic interactions of the components of Ni3S2 and the performance of electrocatalysts for water hydrolysis,with a view to promoting the development of high-efficiency water hydrolysis catalysts,ultimately replacing noble metal based electrocatalysts,and making the practical and widespread application of water hydrolysis electrolyzers a reality.The main research results of this article are as follows:Obtaining oxygen evolution(OER)catalysts with high stability,low cost,and high performance is the key to electrocatalytic water decomposition for oxygen production.Ni3S2(101)crystal surface is considered to be an ideal catalyst for oxygen evolution reaction due to its good conductivity and stability.During the experimental preparation process,defects are inevitable,and the S vacancy is the most common.In this paper,the influence of S vacancy on the crystal surface of Ni3S2(101)was studied by first principles,and O atom substitution doping was proposed to compensate for the vacancy and improve the catalytic activity of the system.The results show that vacancies destroy the stability of the system,and oxygen containing intermediates are easily attracted to vacancies during OER to compensate for the structural defects caused by vacancies;By comparing the free energy of the intermediate with the ideal value,it was found that the vacancy greatly enhanced the interaction between the Ni3S2(101)crystal surface and the intermediate,but the desorption became difficult.Therefore,the over potential of the OER reaction was significantly enhanced,and the catalytic activity decreased.Furthermore,we use O atom substitutional doping to compensate the S vacancy,and compensation is conducive to improving the stability of the system,effectively improving the desorption capacity of the active site,and greatly improving the catalytic activity of the defect system.Defects affect the catalytic performance of systems by changing their structure,but not all systems have improved their catalytic activity.Defect compensation is an effective method to improve the catalytic activity of systems.This provides an important reference for designing efficient oxygen evolution properties of Ni3S2-based two-dimensional semiconductors. |
