Abstract:Because of the special heterojunction structure, SnO2-NiO has been used as gas sensing material and supercapacitor electrode addition material.But it has been studied less in electrocatalytic oxidation of industrial wastewater. The effect of SnO2-NiO-IrO2 electrode on the electrocatalytic methyl orange solution was studied by adding active oxide IrO2. SnO2-NiO-IrO2/Ti electrodes were prepared by thermal decomposition method. SEM, XRD, XPS, BET, CV, EIS, LSV, TOC, UV, and strongthen life were used to test the microstructure and the catalytic performance.It’s shown that IrO2 changeg the concentration of oxygen vacancies in the SnO2 lattice, resulting in forming the impurity defects in the crystal structure, refining the grains, and then increasing the specific surface area and conductivity of the composite oxide coatings. The diffusion rate of the active matter to the inner layer was increased too. Thus, the catalytic activity and stability of the electrode were optimized.The electrode with IrO2 content of 23.1% had the best degradation effect on methyl orange, which had a maximum degradation rate of 93% and a maximum service life of 678 hs.