Photoassisted Reduction Synthesis of Pt@SnO2/Graphene Catalysts with Excellent Activities toward Methanol Oxidation

Photoassisted reduction, as an indispensable supplement to traditional chemical reduction, is a significant technique for regulating the interfacial interaction of active substances in the hybrid electrocatalysts toward methanol oxidation reaction (MOR). In this work, the well-hierarchical heterostructure of Pt@SnO2/graphene was successfully developed through the usage of the first hydrothermal and subsequent ultraviolet light (UV) excitation process. It was found that Pt particles with an average diameter size of 2.41 nm could be effectively trapped on the surface of semiconducting SnO2 nanocrystals (NCs). Besides, the small SnO2 NCs with an even distribution provided great opportunities for the accessible regulation from UV irradiation, thus endowing them with high contents of oxygen vacancies, broadened valence band, and inseparably interfacial effect that contributed to the improvement of electrical conductivity for the composite catalysts. Benefitting from the synergistic effect from each component, the obtained catalysts not only displayed a large electrochemically active surface area (ECSA) value of 80.7 m(2) g(-1) and excellent mass activity of 1833.6 mA mg(-1) but also showed desirable long-term durability and poisoning tolerance. For the further enhancement of electrochemical performance, electro-photo synergistic catalysis was also adopted by employing UV during the electrochemical measurements.