Light-driven synthesis of C2H6 from CO2 and H2O on a bimetallic AuIr composite supported on InGaN nanowires

Generation of C2+ 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 CO2, achieving C–C coupling by insertion of CO2 into –CH3. Due to a combination of optoelectronic and catalytic properties, the assembly of AuIr with InGaN nanowires on silicon enables the achievement of a C2H6 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 CO2 and H2O is achieved without any other energy inputs. This work provides a carbon-negative path for producing higher-order carbon compounds. Producing valuable chemicals from carbon dioxide, water and sunlight through artificial conversion schemes remains a challenging and ambitious goal in photocatalysis. Here, the authors introduce an effective approach for the synthesis of C2+ compounds using a binary AuIr catalyst in combination with InGaN nanowires.