Preparation of Co-S/NixSey/C@TiO2 composite electrode and the performance improvement strategies for the electrooxidation of H2O2

Background: The cleanliness and ease of storage and transportation of H2O2 make it a promising fuel of fuel cell, but improving the catalytic activity of H2O2 electrooxidation is a prerequisite.Method: The Co-S/NixSey/C@TiO2 electrode was prepared by "vapor deposition" and "two-step electrodeposi- tion", and the electrode was scaled up and fabricated into a rotating cylinder electrode to improve the catalytic performance of H2O2 electrooxidation. Significant findings: The presence of Se-Se bonds and the synergistic effect of Co-S compound and NixSey gave the electrode a reduced oxidation potential for the electrooxidation of H2O2. The three-dimensional (3D) structure of the electrode facilitated the exposure of the catalyst active site, and the loading of Co-S compound improved the hydrophilicity of electrode. It's important to note that an original rotating cylinder electrode system was fabricated using an enlarged Co-S/NixSey/C@TiO2 electrode to weaken concentration polarization and reduce bubble adsorption on the electrode surface. Through the study, rotation of electrode and circulation of reaction solution exhibit positive effect for the electrooxidation reaction. Especially with a rotation speed of 37 r min-1 of electrode, the performance was improved by 85%. This study provides new strategies for improving the per- formance of H2O2 electrooxidation, which is of high research significance.