However, artificial photosynthesis is quite complex and involves numerous steps. Moreover, it is difficult to selectively synthesize target compounds with C–C bonds as several AP intermediates can provide thermodynamically favorable C1 products.
Angewandte Chemie International Edition published the findings on February 14th, 2023.
The suggested composite catalyst, which consists of a few-layer graphene overlayer, an interfacial layer (IL), and a SiC substrate, can assist in achieving precise control of the active intermediates for C–C coupling.
An ideal IL structure makes it simple to transmit photogenerated electrons from the SiC substrate to the active sites on the graphene overlayer. Due to their strong adsorption at the reaction’s active sites and the high electron density of the graphene surface, reaction intermediates can then be effectively created and maintained.
The researchers discovered that CH3OH production was reduced significantly in favor of C–C coupling. Under simulated solar irradiation with a modest bias (–50 mV bias vs. Ag/AgCl) and ambient conditions, C2H5OH was exclusively produced with a selectivity of >99% and a CO2 conversion rate of 17.1mmol gcat–1h–1.
Therefore, the optimal catalyst’s photoelectrocatalytic performance in creating C2 products from CO2 was at least two orders of magnitude greater than that of the most advanced AP catalysts.
Journal Reference:
Feng, G., et al. (2023) Highly Selective Photoelectroreduction of Carbon Dioxide to Ethanol over Graphene/Silicon Carbide Composites. Angewandte Chemie International Edition. doi:10.1002/anie.202218664.