Construction Of Nano-structure RuO₂-Based Anode Coating For Electrocatalytic Oxygen Evolution Reaction

RuO₂-based precious metal oxide anodes have become the most successful oxygen evolution electrocatalyst for commercialization in the past few decades due to their excellent electrocatalytic activity,strong acid resistance and long service life in severe acid working environment.However,the high cost and the poor stability of single-component RuO₂coatings at high current densities limit their large-scale application.In this paper,three-dimensional composite anodes were prepared by pyrolysis and electrodeposition of RuO₂-based nanoparticles on the surface of the three-dimensional TiO₂ and Co₃O₄ interlayers which were introduced by hydrothermal treatment and electrodeposition,respectively.The surface morphology and microstructure of the composite anodes were studied by XRD,SEM,and TEM.Besides,the electrocatalytic oxygen evolution performance of the fabricated anodes in acid environment were investigated by LSV,CV,EIS and cyclic stability tests to reveal the effects of microstructure of the synthesized anodes on their electrochemical performance.TNW@RuO₂ nanowire core-shell structure was designed through cyclic voltammetry electrodeposition of RuO₂ on the surface of the TiO₂ nanowire arrays introduced by hydrothermal treatment.The results showed that TNW@RuO₂ prepared by 720 cycles of cyclic voltammetry electrodeposition exhibited the best OER performance,which operates for OER in H₂SO₄with the lowest potential(1.340 V(vs.SCE))at stable current density(10m A/cm²).In addition,TNW@RuO₂ showed better OER stability with an ultralow additional potential of 0.298%after 1000 cycles'CV tests,one order of magnitude lower than that of the Ti@Ru+RuO₂(3.67%)without TNW interlayer.A facile strategy for the design of durable three dimensional(3D)TiO₂@RuIr composed of fine and dispersive RuO₂/IrO₂ mixed nanocrystalline with the diameter of 10?20 nm through the pyrolysis of RuO₂/IrO₂ precursors on the in-situ hydrothermal firm TiO₂nanoarrays is reported.The results showed that the formation of the cracks which occurs frequently during the pyrolysis process can be inhibited by introducing TiO₂ nanoarrays.Among the anodes with TiO₂nanosheets,nanosheet-wires and nanowires interlayers,TNW@RuIr showed the highest electrochemical activity,which displays the lowest potential of 1.409 V(vs.SCE)at 10 m A/cm².Besides,TNW@RuIr exhibited an enhanced OER stability with an ultralow additional potential of 0.07%after the 1000 cycles'CV test in 0.5 M H₂SO₄,two orders of magnitude lower than that of the Ti/RuIr(2.19%)without the TNW interlayer.3D Co@RuIr electrode was successfully synthesized through pyrolysis of RuO₂/IrO₂precursors on the surface of Co₃O₄ nanosheets prepared by potentiostatic electrodeposition.The results showed that fine RuO₂/IrO₂ nanoparticles were evenly dispersed on the surface of the Co₃O₄ nanosheets after three paintings of RuO₂/IrO₂ precursors,and the resulted 3D Co@RuIr catalyst exhibited highly active toward OER in 0.5 M H₂SO₄ with the lowest potential(1.326 V(vs.SCE))at 10 m A/cm².In addition,though both Co@RuIr and Ti/RuIr showed the similar stability,Co@RuIr displayed high active towards oxygen evolution reaction with a lower potential at 10 m A/cm²,118 m V lower than that of the Ti/RuIr.