One-Pot Synthesis of PtIn/3D-GNs Composites with High Alloying Degree for Electro-Photo Synergistic Catalysis
In this work, one-pot solid phase reaction was used to synthesize PtIn/3D-GNs composites with different alloying degree. The as-synthesized composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and X-ray photoelectron spectroscopy (XPS). The results indicate that PtIn alloy was formed in the PtIn/3D-GNs composites. However, In (0) content in the composites (denoted as PtIn/3D-GNs (O)) when In2O3 was used as a precursor of In is almost twice as much as that in the composites (denoted as PtIn/3D-GNs (S)) using In(NO3)3 as a precursor of In, which indicates the higher Pt-In alloying degree in PtIn/3D-GNs (O). Electrochemical tests show that PtIn/3D-GNs composites exhibit superior electrocatalytic activity, better stability and enhancing antipoisoning ability toward methanol oxidation reaction (MOR) in comparison with Pt/3D-GNs and the commercial Pt/C. Interestingly, the synergistic effect between the charge separation of In2O3 and the SPR excitation of In (0) under light irradiation contributes to their good electro-photo catalytic performance under simulated sunlight irradiation. Especially, the higher Pt-In alloying degree in PtIn/3D-GNs (O) is in favor of its better conductivity, which is responsible for its more efficient electro-photo catalytic properties.