Selective Photocatalytic Oxidation of Methane to Oxygenates over Cu–W–TiO₂ with Significant Carrier Traps

Direct selective methane photooxidation to liquid oxygenates with high productivity and selectivity under mild reaction conditions is highly urgent but remains challenging. Herein, a Cu and W codoped TiO₂ (Cu–W–TiO₂) photocatalyst was fabricated to enable aerobic oxidation of methane into oxygenates with limited formation of CO₂ under ambient temperature. A high oxygenate productivity of 34.5 mmol g^–1 with a remarkable selectivity of 97.1% was achieved over the Cu–W–TiO₂ photocatalyst. Based on structural characterizations and mechanism studies, it was suggested that the Cu species acted as hole traps, while oxygen vacancies and the W⁶⁺-dopant state worked as electron traps. The inhibited recombination of photogenerated carriers contributed to enhanced photocatalytic efficiency. The modulated electronic and band structure promoted the activation of methane and hindered the overoxidation of oxygenates.