Preparation And Electrocatalytic Oxygen Evolution Properties Of FeSe-based Amorphous Films

In the field of new energy,the efficiency of hydrogen production from electrolytic water is greatly limited by the rate of anodic oxygen evolution reaction.The study of efficient oxygen evolution catalyst can provide a good impetus for the development of renewable energy system.As we know,the commercial application of traditional noble metal OER catalysts such as Ir,Ru and their oxides has great limitations.Therefore,it is of significance to study transition non-noble metal OER catalysts.Based on this purpose,we focused on the catalytic performance of(Fe_0.5Co_0.5)_80-xNi_xSe₂₀ amorphous thin film oxygen evolution catalyst.In this dissertation,we use vacuum magnetron sputtering method to prepare(Fe_0.5Co_0.5)_80-xNi_xSe₂₀ thin films on carbon fiber paper(CFP).Firstly,we investigated the effect of substrate temperature on the OER electrocatalytic performance of Fe₄₀Co₄₀Se₂₀/CFP composite when x is 0 in(Fe_0.5Co_0.5)_80-xNi_xSe₂₀.In the experiment,three substrates were set at 308 K,393 K and 573 K,respectively.The structure and electrocatalytic properties of the samples were characterized.It was found that the Fe₄₀Co₄₀Se₂₀/CFP amorphous film and carbon fiber paper composite structure prepared at 393 K had the most comprehensive properties.The overpotential was 307 m V at 10m A cm^-2 current density and could be sustained and stable.The results show that the activation area and electrochemical impedance both affect the final OER electrocatalytic performance of the samples.Properly increasing the substrate temperature is conducive to improving the catalytic activity of amorphous film catalysts.At the same time,we also studied the influence of the content of Ni on the electrocatalytic performance of OER with the composite structure of(Fe_0.5Co_0.5)_80-xNi_xSe₂₀/CFP amorphous film and carbon fiber paper composite structure.In the experiment,we controlled the content of Ni element to be x=0,4,12 and 25,respectively,and characterized the state of the sample and their catalytic performance of electrochemical OER.The experimental results show that the appropriate increase of Ni content not only increases the impedance of the sample,but also introduces more active sites for the sample.With the increase of Ni content,(Fe_0.5Co_0.5)_80-xNi_xSe₂₀/CFP's OER catalytic performance first increases and then decreases,reaching its maximum at x=12,overpotential at 10 m A cm^-2 current density in 1.0 M KOH solution is 291 m V,Tafel slope is 42.3 m V dec^-1,and it has good catalytic stability.It can work stably for more than 10 hours under the load of this current density.