Selective light-driven methane oxidation to ethanol

Methane (CH₄) photocatalytic upgrading to value-added chemicals, especially C₂ products, is significant yet challenging due to sluggish energy/mass transfer and insufficient chemical driven-force in single photochemical process. Herein, we realize solar-driven CH₄ oxidation to ethanol (C₂H₅OH) on crystalline carbon nitride (CCN) modified with Cu₉S₅ and Cu single atoms (Cu₉S₅/Cu-CCN). The integration of photothermal effect and photocatalysis overcomes CH₄-to-C₂H₅OH conversion bottlenecks, with Cu₉S₅ as a hotspot to convert solar-energy to heat. In-situ characterizations demonstrate that Cu single atoms play as electron acceptor for O₂ reduction to ·OOH/ · OH, while Cu₉S₅ acts as hole acceptor and site for CH₄ adsorption, C - H activation, and C - C coupling. Theoretical calculations demonstrate that Cu₉S₅/Cu-CCN reduces C - C coupling energy barrier by stabilizing ·CH₃ and ·CH₂O. Impressively, C₂H₅OH productivity reaches 549.7 μmol g^-1 h^-1, with selectivity of 94.8% and apparent quantum efficiency of 0.9% (420 nm). This work provides a sustainable avenue for CH₄ conversion to value-added chemcials.