Sustainable all-weather CO₂ utilization by mimicking natural photosynthesis in a single material

Solar-driven CO₂ conversion into hydrocarbon fuels is a sustainable approach to synchronously alleviating the energy crisis and achieving net CO₂ emissions. However, the dependence of the conversion process on solar illumination hinders its practical application due to the intermittent availability of sunlight at night and on cloudy or rainy days. Here, we report a model material of Pt-loaded hexagonal tungsten trioxide (Pt/h-WO₃) for decoupling light and dark reaction processes, demonstrating the sustainable CO₂ conversion under dark conditions for the first time. In such a material system, hydrogen atoms can be produced by photocatalytic water splitting under solar illumination, stored together with electrons in the h-WO₃ through the transition of W⁶⁺ to W⁵⁺ and spontaneously released to trigger catalytic CO₂ reduction under dark conditions. Furthermore, we demonstrate using natural light that CH₄ production can persist at night and on rainy days, proving the accomplishment of all-weather CO₂ conversion via a sustainable way.