A Ni-O-Ag photothermal catalyst enables 103-m ² artificial photosynthesis with >17% solar-to-chemical energy conversion efficiency

Abstract

The scalable artificial photosynthesis composed of photovoltaic electrolysis and photothermal catalysis is limited by inefficient photothermal CO 2 hydrogenation under weak sunlight irradiation. Herein, NiO nanosheets supported with Ag single atoms [two-dimensional (2D) Ni 1 Ag 0.02 O 1 ] are synthesized for photothermal CO 2 hydrogenation to achieve 1065 mmol g −1 hour −1 of CO production rate under 1-sun irradiation. This performance is attributed to the coupling effect of Ag-O-Ni sites to enhance the hydrogenation of CO 2 and weaken the CO adsorption, resulting in 1434 mmol g −1 hour −1 of CO yield at 300°C. Furthermore, we integrate the 2D Ni 1 Ag 0.02 O 1 -supported photothermal reverse water-gas shift reaction with commercial photovoltaic electrolytic water splitting to construct a 103-m 2 scale artificial photosynthesis system (CO 2 + H 2 O → CO + H 2 + O 2 ), which achieves more than 22 m 3 /day of green syngas with an adjustable H 2 /CO ratio (0.4-3) and a photochemical energy conversion efficiency of >17%. This research charts a promising course for designing practical, natural sunlight–driven artificial photosynthesis systems.