Study On Structural Control Based On Vanadium Nitride Catalyst And Their Application In Hydrogen Evolution Reaction

With the rapid development of China's economy and society,the demand for energy is increasing,and environmental problems are becoming more and more serious.The development and utilization of high-clean new energy fuel can effectively alleviate the energy crisis and environmental pollution.It is a new science and technology,which is a manifestation of the wisdom and innovation of researchers,and it will be an important change in the process of human civilization.Hydrogen energy is a abundant,diverse,high calorific value,renewable,clean and pollution-free energy source.In the vigorous promotion of hydrogen energy,storage and transportation is the core guarantee for hydrogen energy application.At present,the preparation of hydrogen by electrolyzed water is the most valuable means of storage and conversion of hydrogen.Electrocatalysts play a pivotal role in hydrogen evolution,directly affecting the progress of the entire reaction.It's well-known that Platinum-based materials have superior performance in hydrogen evolution.However,due to their high price and scarce resources,they cannot be used vigorously.Therefore,it is necessary to seek a high-efficiency catalyst which is rich in resources,low in price,long in cycle life,and friendly to environment,so that improving the development of hydrogen production in electrolyzed water in the future.Therefore,research and development of non-precious metal catalysts with high catalytic efficiency have become the focus in hydrogen evolution.Herein,this paper explores the performance of transition metal vanadium nitride in hydrogen evolution reaction.The specific research contents are as follows:?1?.With ammonium polyvanadate?NH₄?₂V₃O₈ and NH₄VO₃ as precursor,we have successfully proposed a three-dimensional porous vanadium nitride?VN?octahedral structure,which is prepared by calcination treatment.The VN catalyst showed good electrocatalytic activity with a small overpotential of 94.0 mV at 10 mA cm^-2,the corresponding low Tafel slope of 54.6 mV dec^-1,and stability in acidic media up to 80 h,which is superior to many reported nitrides.In addition,the excellent catalytic performance of VN can be attributed to its porous characteristics?platinum-like properties?,and the product vanadium nitride octahedron retains the uniform size of the precursor,the morphological features,and the formation of porous features,thereby increasing the specific surface area increases the total number of active sites,and these properties are indispensable for the superior performance of electrochemical performance.?2?.With Zn₃?OH?₂?V₂O₇??H₂O?₂ as the precursor,the vanadium nitride nanosheets catalyst with nanostructure was successfully prepared for the first time.The precursor is very thin nanosheets,which are then calcined at a certain temperature in an ammonia atmosphere to obtain 2D porous VN nanosheets catalyst.The VN catalyst exhibits superior hydrogen evolution reaction?HER?activity,including a low overpotential of90.0 mV at 10 mA cm^-2,corresponding low Tafel slope of 47.7 mV dec^-1 and good cycling stability.This solution also increases the activity of the catalyst by preparing a uniformly porous material to increase the specific surface area of the material.In general,the preparation methods of two-dimensional porous VN-650 nano-mesh and three-dimensional porous VN-720 octahedron are simple and easy to operate,the cost is low,and both exhibit good catalytic activity in hydrogen evolution reaction.