Photothermal CO₂ conversion to ethanol through photothermal heterojunction-nanosheet arrays

Photothermal CO₂ conversion to ethanol offers a sustainable solution for achieving net-zero carbon management. However, serious carrier recombination and high C-C coupling energy barrier cause poor performance in ethanol generation. Here, we report a Cu/Cu₂Se-Cu₂O heterojunction-nanosheet array, showcasing a good ethanol yield under visible-near-infrared light without external heating. The Z-scheme Cu₂Se-Cu₂O heterostructure provides spatially separated sites for CO₂ reduction and water oxidation with boosted carrier transport efficiency. The microreactors induced by Cu₂Se nanosheets improve the local concentration of intermediates (CH₃* and CO*), thereby promoting C-C coupling process. Photothermal effect of Cu₂Se nanosheets elevates system's temperature to around 200 ^°C. Through synergizing electron and heat flows, we achieve an ethanol generation rate of 149.45 µmol g^-1 h^-1, with an electron selectivity of 48.75% and an apparent quantum yield of 0.286%. Our work can serve as inspiration for developing photothermal catalysts for CO₂ conversion into multi-carbon chemicals using solar energy.