Molecularly engineered photocatalyst sheet for scalable solar formate production from carbon dioxide and water

Harvesting solar energy to convert CO2 into chemical fuels is a promising technology to curtail the growing atmospheric CO2 levels and alleviate the global dependence on fossil fuels; however, the assembly of efficient and robust systems for the selective photoconversion of CO2 without sacrificial reagents and external bias remains a challenge. Here we present a photocatalyst sheet that converts CO2 and H2O into formate and O2 as a potentially scalable technology for CO2 utilization. This technology integrates lanthanum- and rhodium-doped SrTiO3 (SrTiO3:La,Rh) and molybdenum-doped BiVO4 (BiVO4:Mo) light absorbers modified by phosphonated Co(ii) bis(terpyridine) and RuO2 catalysts onto a gold layer. The monolithic device provides a solar-to-formate conversion efficiency of 0.08 ± 0.01% with a selectivity for formate of 97 ± 3%. As the device operates wirelessly and uses water as an electron donor, it offers a versatile strategy toward scalable and sustainable CO2 reduction using molecular-based hybrid photocatalysts. Selective photocatalytic conversion of CO2 into fuels without using sacrificial reagents and external bias has proved difficult. Addressing these challenges, Wang and colleagues fabricate wireless photocatalyst sheets comprising a molecular cobalt catalyst and metal oxide semiconductors that convert CO2 and H2O into formate and O2.