Preparation Of Carbon-supported Nickel-based Composites For Hydrogen Evalution Reaction

Human dependence on fossil fuel energy has an adverse impact on the environment,demanding transition to clean and renewable energy in the future.As a carrier of renewable energy,hydrogen is considered to be the most promising substitute for hydrocarbons.Among many hydrogen generation processes,water splitting is an environmental friendly technology for large-scale producing hydrogen from renewable energy,which meets the goals of energy conservation and emission reduction.At present,even though platinum-based precious metal materials are still the most efficient catalyst,the cost causes a key barrier to actual large-scale application.Therefore,it is the optimal solution to search for efficient and durable electrocatalysts toward hydrogen evolution reaction or oxygen evolution reaction with low cost for the successful realization of H₂ mass production.The key to high activity and stability electrocatalytic catalysts rest with stable structure,good conductivity and abundant catalytic sites.Based on the above discussion,this article aims to explore the preparation of carbon supported nickel-based nanomaterials and electrocatalytic performance.The main research contents are as follows:（1）Using flake graphene as the conductive substrate and sodium hypophosphite as the phosphorus source,V-doped Ni₂P/G was successfully fabricated through simple solvothermal and thermal treatment.Compared with Ni₃V₂O₈/G and Ni₂P/G,V-Ni₂P/G exhibited better hydrogen evolution performance in alkaline conditions from the electrochemical test.The excellent activity was mainly attributed to the doping of V increased the P content of material so as to effectively improved the performance of hydrogen evolution reaction.In addition to,the fine nanoparticles were dispersed on highly conductive graphene,which was conducive to the rapid transfer of charges and expose a large number of active sites.（2）Ni Fe/Mo₂C heterostructure wrapped with nitrogen-doped carbon nanotubes（Ni Fe/Mo₂C@NCNT）was successfully synthesized through high-temperature pyrolysis treatment.Ni Fe/Mo₂C@NCNT exhibited high performance toward HER and OER respectively,which could be ascribed to the synergistic effect of multiple catalytic active centers,N-doped carbon nanotubes encapsulating shell and abundant Ni Fe/Mo₂C heterogeneous interface.Moreover,when the bifunctional Ni Fe/Mo₂C@NCNT were applied as electrode for overall water splitting,the corresponding water electrolyzer could be driven at a low voltage of 1.554 V with high durability in alkaline media.