Preparation Of Transition Metal Phosphide/Doped Graphene Composites And Study On Their Hydrogen Evolution Properties

With the progress and development of society,the demand for energy is growing.At present,it is mainly based on non-renewable and environmentally polluting fossil energy,so it is important to explore sustainable and environmentally friendly clean energy.The energy density of hydrogen is extremely high,and the combustion product is only water,which is a very promising new energy source.Among them,the production of hydrogen by electrolyzed water is a very effective way to produce hydrogen,but it requires an electrocatalyst with particularly high activity.At present,the most active electrocatalysts are precious metal catalysts represented by platinum,but their high price and low reserves limit their applications.Therefore,it is important to find non-precious metal catalysts with low price,high activity and abundant reserves.Because of its special structure,transition metal phosphide is called "quasi-platinum catalyst".Graphene is a particularly excellent catalyst support,and nitrogenand sulfur-doped graphene can provide more active centers for the catalyst,thereby improving the catalytic performance of the catalyst.This paper explores the preparation and hydrogen evolution properties of transition metal phosphide/doped graphene composites.The main research contents are as follows:1.The best experimental conditions for the preparation of nickel phosphide?Ni₂P?by hydrothermal method were explored.The test and analysis results showed that the best experimental conditions were: 5: 1 phosphorus-nickel molar ratio,12 hours reaction time,and140 ?;2.Improved hummers method was used to prepare graphene oxide?GO?,and nitrogen-doped reduced graphene oxide?NRGO?and nitrogen-sulfur double-doped reduced graphene oxide?NSRGO?were prepared by hydrothermal method.3.The optimal loading of Ni₂P on RGO was explored,and Ni₂P/NRGO and Ni₂P/NSRGO composite catalysts were prepared based on this.Ni₂P/NSRGO showed very excellent catalytic performance.Graphite-N,pyrrole-N,pyridine-N,and thiophene-S have played a vital role in improving catalyst activity;4.In the synthesis of Ni₂P,cobalt is introduced to form NiCoP.On this basis,NiCoP/RGO,NiCoP/NRGO and NiCoP/NSRGO composite catalysts were prepared.NiCoP/NSRGO shows the best catalytic performance in this paper.