Light-driven synthesis of C 2 H 6 from CO 2 and H 2 O on a bimetallic AuIr composite supported on InGaN nanowires

Generation of C 2+ compounds from sunlight, carbon dioxide and water provides a promising path for carbon neutrality. Central to the construction of a rational artificial photosynthesis integrated device is the requirement for a catalyst to break the bottleneck of C–C coupling. Here, based on operando spectroscopy measurements, theoretical calculations and feedstock experiments, it is discovered that gold, in conjunction with iridium, can catalyse the reduction of CO 2 , achieving C–C coupling by insertion of CO 2 into –CH 3 . Due to a combination of optoelectronic and catalytic properties, the assembly of AuIr with InGaN nanowires on silicon enables the achievement of a C 2 H 6 activity of 58.8 mmol g −1 h −1 with a turnover number of 54,595 over 60 h. A light-to-fuel efficiency of ~0.59% for solar fuel production from CO 2 and H 2 O is achieved without any other energy inputs. This work provides a carbon-negative path for producing higher-order carbon compounds.