Synergistic Enhancement\nof Oxygen Evolution by S‑Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene Folded Nanosheets\nSupported by Cobalt Hydroxide Nanoparticles

The metal active site-induced adsorbate evolution mechanism\n(AEM)\nand the lattice oxygen-mediated mechanism (LOM) can significantly\nimprove the performance of the electrocatalytic oxygen evolution reaction,\nbut the LOM is not easily triggered on the AEM. Herein, a unique mixture\nof transition metal Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene and cobalt hydroxide is introduced. A sulfur-doped Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene substrate\nwith a clear composition and layered structure was formed on Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene thin-layer\nnanosheets by the sulfur template method for the study of alkaline\nelectrochemical oxygen evolution. Sufficient metal active sites, robust\nstructures, good electrochemical kinetics, and increased catalytic\nactivity are provided by the resulting nanohybrids. Significantly,\nthe sulfur-doped MXene substrate has more abundant oxygen vacancies\nand better hydrophilicity; this interaction is more favorable for\nimproving the electrochemical performance of the alkaline oxygen evolution\nreaction (OER). The results of electrochemical tests support the hypothesis\nthat the interfacial electron coupling of two different components\nand the doping of the oxygen vacancy may optimize the adsorption energy\nof H<sub>2</sub>O and *OH, leading to a small overpotential of 207\nmV at 10 mA cm<sup>–2</sup>, and the material is stable for\nthe OER. This has great potential for the development of electrocatalysts\nwhere both the AEM and the LOM work together and their applications\nin energy-related fields.