Research on preparation and OER properties of vanadium doped cobalt iron layered double hydroxide
Exploiting environmentally friendly and relatively low-toxicity oxygen evolution reaction(OER)electrocatalysts is currently one of the biggest difficulties in water splitting.In this work,cobalt iron layered double hydroxide(CoFe LDH)and vanadium-doped cobalt iron layered double hydroxide(V-CoFe LDH)nanosheets are in situ grown on nickel foam(NF)by electrodeposition as an effective OER catalyst.When CoFe LDH and V-CoFe LDH samples are used as electrocatalysts,they both ex-hibit excellent OER performance.In an alkaline media,when the current density is 100 mA·cm-2,the overpotentials of CoFe LDH and V-CoFe LDH are small overpotentials of 396 mV and 356 mV,re-spectively.Tafel slopes of CoFe LDH and V-CoFe LDH are 224 mV·dec-1 and 210 mV·dec-1,respect-ively.The electrochemical activity specific surface area of V-CoFe LDH electrocatalysts is higher than CoFe LDH electrocatalysts.Moreover,the V-CoFe LDH electrocatalyst has better wetting properties for the electrolyte.These all indicate that the introduction of V helps to enhance the OER performance of the material.Density functional theory calculations and experimental results have shown that the dop-ing of V not only optimizes the electronic structure of the material,enhances conductivity,but also re-duces adsorption energy and enhances the contact between the catalyst and electrolyte.This work demonstrates that V-CoFe LDH is a highly promising OER electrocatalyst.
electrocatalystcobalt iron layered double hydroxidevanadium dopingoxygen evolution reactionconductivity
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