Generation of C2+ compounds using sunlight, carbon dioxide, and water provides a promising path for carbon neutrality. The exploration of a catalyst to break the bottleneck of C-C coupling, for constructing a rational artificial photosynthesis integrated device, is at the core. Herein, based on operando spectroscopy measurements, theoretical calculations, and feedstock experiments, it is discovered that gold, in conjunction with iridium, can catalyze the reduction of CO2, achieving C-C coupling by insertion of CO2 into -CH3. Owing to a combination of optoelectronic and catalytic properties, the assembly of AuIr with InGaN nanowires on silicon (AuIr@InGaN NWs/Si) enables the achievement of a C2H6 activity of 58.8 mmol‧g-1‧h-1 with a turnover number of 54,595 over 60 hours. A light-to-fuels efficiency of ~0.59% for solar fuels production from CO2 and H2O is achieved without any other energy inputs. This work provides a carbon-negative path for producing higher order C compounds.
