Preparation Of Bimetallic Compounds Based On Vanadium For Electrocatalytic Water Splitting

The problem of energy crisis is becoming more and more serious,forcing mankind to search for efficient and clean renewable energy urgently.Hydrogen is a very important clean energy,which has attracted much attention because of its high energy and non-pollution to the environment.As a clean and renewable energy,hydrogen can be used as an alternative energy source for traditional fossil energy such as natural gas,coal and oil.Among many methods of hydrogen preparation,electrocatalytic water spitting for hydrogen evolution reaction is considered to be the most suitable strategy.So we need to study safe,efficient and stable catalysts urgently.Noble metals such as platinum?Pt?and ruthenium oxide?RuO₂?have been recognized as the most efficient catalysts for the electrocatalytic water spitting.However,their high cost and scarce production make them unable to be widely used in the electrocatalytic water spitting equipment.Therefore,people have been expecting to develop new,inexpensive and abundant efficient catalysts to replace precious metals.In recent years,some new nano-catalysts have been synthesized for the electrocatalytic water spitting.Nano-materials have excellent catalytic performance for hydrogen evolution reaction due to their special microstructures.Layered two-dimensional materials,as nano-materials with special structures,have good application prospects for hydrogen evolution reaction catalysis.Transition metal layered dihydroxides or hydroxyl oxides,transition metal oxides and transition metal phosphorus sulfides all have good catalytic performance for hydrogen evolution reaction.In this paper,three kinds of electrocatalysts were synthesized for the electrocatalytic water splitting.1.Preparation and electrocatalytic decomposition of transition metal vanadium hydroxide?VOOH?and its doping.Hydroxyvanadium oxide?VOOH?hollow nanospheres were synthesized by one-step hydrothermal method using ammonium metavanadate?NH₄VO₃?,hydrochloric acid?HCl?and hydrazine hydrate?N₂H₄.H₂O?.Adding Fe?Fe-VOOH?can increase the active site and enhance the conductivity of the catalyst.Because of the electron transfer between V and Fe atom,the incorporation of Fe can further improve the catalytic performance of electrocatalytic water splitting.2.Preparation and performance of trivalent oxides?V₂O₃?of transition metal vanadium?V?and their dopants?Fe-V₂O₃?.VOOH and Fe-VOOH were prepared by hydrothermal method.The final samples were annealed in a high temperature tubular furnace under the protection of nitrogen at 500?for the study of electrocatalytic water splitting.3.P in transition metal phosphides not only acts as hydrogen proton acceptor,but also limits the non-localization of metal atoms,controlling electron transport.If an anion?such as S?with stronger electronegativity is introduced into transition metal phosphides,the electron delocalization of metal atoms will be enhanced and the catalytic performance of hydrogen evolution reaction will be enhanced.In addition,because some nano-scale carbon materials?such as two-dimensional graphene?have topological defects,if they are combined with transition metal phosphides,it can greatly improve the electrocatalytic performance and stability.Therefore,we mainly studied the preparation and electrocatalytic performance of NiPS₃ combined with defective graphene?DG?.