A photothermal catalyst system, Cu/Cu₂Se-Cu₂O heterojunction-nanosheet arrays (Cu-CSCO HNA), was developed for efficient conversion of CO₂ to ethanol under visible-near-infrared light without external heating. The system combines a Z-scheme heterostructure of Cu₂Se-Cu₂O, which facilitates spatially separated CO₂ reduction and water oxidation, with photothermal effects from Cu₂Se nanosheets that elevate the system temperature to around 200°C. This enhances carrier transport efficiency and promotes C-C coupling, leading to 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%. The Cu-CSCO HNA system also features microreactors formed by nanosheet gaps, which increase the local concentration of intermediates (CH₃* and CO*), further enhancing ethanol production. The catalyst demonstrates excellent stability and performance under natural solar conditions, with ethanol yields of 53.47 μmol g⁻¹ h⁻¹. The study highlights the potential of photothermal catalysts for CO₂ conversion into multi-carbon chemicals using solar energy.A photothermal catalyst system, Cu/Cu₂Se-Cu₂O heterojunction-nanosheet arrays (Cu-CSCO HNA), was developed for efficient conversion of CO₂ to ethanol under visible-near-infrared light without external heating. The system combines a Z-scheme heterostructure of Cu₂Se-Cu₂O, which facilitates spatially separated CO₂ reduction and water oxidation, with photothermal effects from Cu₂Se nanosheets that elevate the system temperature to around 200°C. This enhances carrier transport efficiency and promotes C-C coupling, leading to 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%. The Cu-CSCO HNA system also features microreactors formed by nanosheet gaps, which increase the local concentration of intermediates (CH₃* and CO*), further enhancing ethanol production. The catalyst demonstrates excellent stability and performance under natural solar conditions, with ethanol yields of 53.47 μmol g⁻¹ h⁻¹. The study highlights the potential of photothermal catalysts for CO₂ conversion into multi-carbon chemicals using solar energy.