Construction of a Graphene-Wrapped Pd/SiO2@TiO2 Core–Shell Sphere for Enhanced Photoassisted Electrocatalytic Methanol Oxidation Property

Direct methanol fuel cells (DMFCs) are promising future green energy conversion devices, and their activity and stability can be improved using photofunctional electrodes with the assistance of light illumination. Herein, the graphene-wrapped Pd/SiO2@TiO2 core–shell sphere (PTSG) was synthesized via a facile electrostatic self-assembly method. Benefiting from structural advantages and component optimization, the PTSG exhibits remarkable intrinsic MOR electrocatalytic activity (1569 mA·mg–1) and the 1.88 times enhancement (2921 mA·mg–1) under the light irradiation for a methanol oxidation reaction in the alkaline medium. The metal-support interactions among Pd NPs, SiO2@TiO2, and graphene offer the electrocatalyst more active metallic Pd for methanol oxidation. Moreover, further analysis reveals that SiO2@TiO2 endows the catalyst with more surface oxygen-containing groups, high methanol-adsorption capacity, and high light utilization compared to the pure TiO2, which enables the PTSG with more available active sites, superior durability, and light harvesting. This work provides a new sight for designing high-performance photoassisted MOR electrocatalysts.