Synthesis of Different Pt‐ZnO Binary Composites for Synergistic Photo‐Electrocatalytic Oxidation of Methanol in Alkali

Various compositions of Pt‐ZnO binary nano composites are synthesized as anode‐catalyst for methanol oxidation reaction (MOR) in alkali under both presence and absence of visible light. Synthesized materials are characterised by various microscopic and spectroscopic techniques. The catalytic capabilities of synthesized anodes are evaluated by cyclic voltametry (CV), chronoamperometry (CA) and electro‐chemical impedance spectroscopy (EIS). CV studies indicate that Pt‐ZnO composite containing 0.6 wt % of Pt displays peak current density (in mAmg−1 of Pt) 427.5 which is 14.84 times greater than that of composite containing 0.1 wt % Pt (28.80) in dark condition and under visible light, 0.4 wt % Pt and 0.6 wt % Pt exhibit 1.89 and 1.28 times greater activity in reference to MOR than that of dark. CA study reveals that 0.6 wt % Pt exhibits steady current density (20.91 mAmg−1 of Pt) 209 times higher compared to that of composite having 0.1 wt % Pt (0.264 mAmg−1 of Pt). The photocurrent response of 0.4 wt % Pt is found the best among the electrodes examined. The EIS data also reveal enhanced interfacial charge transfer in photo‐irradiated electrodes. The HPLC and GCMS studies identify MOR products and help to draw the mechanisms. Photo sensitive electrocatalyst is designed by deposition of nanoparticles of Pt on the surface of semiconductor ZnO nanomaterial for anodic oxidation of methanol (AOM) in alkali under both dark and visible light illumination. The Pt‐ZnO nanocomposite displays higher catalytic performance and greater stability in AOM upon illumination than dark condition. Pt draws photogenerated electron from conduction band of ZnO at the interfacial surface and improves e−‐h+ separation. The study exhibits different selectivity of products in dark and illuminated condition.