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

The scalable artificial photosynthesis composed of photovoltaic electrolysis and photothermal catalysis is limited by inefficient photothermal CO hydrogenation under weak sunlight irradiation. Herein, NiO nanosheets supported with Ag single atoms [two-dimensional (2D) NiAgO] are synthesized for photothermal CO hydrogenation to achieve 1065 mmol g hour 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 and weaken the CO adsorption, resulting in 1434 mmol g hour of CO yield at 300°C. Furthermore, we integrate the 2D NiAgO-supported photothermal reverse water-gas shift reaction with commercial photovoltaic electrolytic water splitting to construct a 103-m scale artificial photosynthesis system (CO + HO → CO + H + O), which achieves more than 22 m/day of green syngas with an adjustable H/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.