Abstract
Methane (CH(4)) photocatalytic upgrading to value-added chemicals, especially C(2) 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 CH(4) oxidation to ethanol (C(2)H(5)OH) on crystalline carbon nitride (CCN) modified with Cu(9)S(5) and Cu single atoms (Cu(9)S(5)/Cu-CCN). The integration of photothermal effect and photocatalysis overcomes CH(4)-to-C(2)H(5)OH conversion bottlenecks, with Cu(9)S(5) as a hotspot to convert solar-energy to heat. In-situ characterizations demonstrate that Cu single atoms play as electron acceptor for O(2) reduction to ·OOH/ · OH, while Cu(9)S(5) acts as hole acceptor and site for CH(4) adsorption, C - H activation, and C - C coupling. Theoretical calculations demonstrate that Cu(9)S(5)/Cu-CCN reduces C - C coupling energy barrier by stabilizing ·CH(3) and ·CH(2)O. Impressively, C(2)H(5)OH 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 CH(4) conversion to value-added chemcials.