Study On The Decoration Of Heterogeneous Elements For Carbon-based Structures At Atomic Level And Their Electrocatalytic Properties

In the 21st century,environmental pollution and energy shortage are the most important issues facing humanity.Hydrogen can be considered as one of the most promising alternative sources of fossil energy.Hydrogen production from electrolysis of water is an ideal hydrogen production method.The reaction rate control step is oxygen evolution reaction.Current commercial oxygen evolution catalysts are noble metal-based catalysts such as Ru and Ir（such as RuO₂ and IrO₂,etc.）,which have disadvantages such as high cost and easy deactivation of the reaction process.These catalysts have slow oxygen evolution rates and excessive oxygen evolution overpotentials.Seriously restricts the application of electrocatalytic water in the actual production,and limits the development of the hydrogen production industry.Therefore,it is of great significance to study the low-cost,high-activity,high-stability non-noble metal oxygen evolution catalysts.The electrocatalytic reaction is mostly a single catalytic site reaction,so the catalytic activity of regulating the catalytic sites is the key issue of improving the catalytic performance of the catalyst.Based on these,this paper mainly modulates the atomic scale active site of carbon-based structure,that is,it modifies the single-atom-level heterogeneous element on the carbon-based structure as the oxygen evolution active site to increase the oxygen evolution activity of the carbon-based structure.The content includes the preparation of single Ni atom modified reduced graphene oxide,Ni-Fe diatomic modified graphene oxide and oxygen-modified carbon cloth as oxygen evolution catalysts.The main research contents and conclusions are as follow:1.We synthesized the single Ni atom modified reduced graphene oxide（SA Ni-O-G）was prepared by ion adsorption as an oxygen evolution catalyst.According to the theoretical calculations and the results of electrocatalytic tests,it is shown that the valence state of modified single Ni atom can significantly affect its electrocatalytic oxygen evolution performance.2.We synthesized the Ni-Fe diatomic modified reduced graphene oxides（SA NixFey/G）by ion adsorption method and studied as oxygen evolution catalysts.It is proved that different single atoms have interactions on the surface of graphene and could improve the OER performance of the catalyst.Among them,under alkaline（1M KOH）conditions,the overpotential of SA Ni_2.6Fe₁/G catalyst were only 200 mV and 301 mV at the OER current densities of 10 mA·cm^-2 and 100 mA·cm^-2,respectively.3.We synthesized the oxygen-modified carbon cloth（OM-CC）by microwave method.It has created a large-scale,low-cost preparation of oxygen-modified carbon-based structures,and has showed good and stable OER performance under both alkaline（1M KOH）and acidic（0.5M H₂SO₄）conditions.