A synergetic cocatalyst for conversion of carbon dioxide, sunlight and water into methanol

The conversion of CO₂ into liquid fuels, using only sunlight and water, offers a promising path to carbon neutrality. An outstanding challenge is to achieve high efficiency and product selectivity. Here, we introduce a wireless photocatalytic architecture for conversion of CO₂ and water into methanol and oxygen. The catalytic material consists of semiconducting nanowires decorated with core-shell nanoparticles, with a copper-rhodium core and a chromium oxide shell. The Rh/CrOOH interface provides a unidirectional channel for proton reduction, enabling hydrogen spillover at the core-shell interface, as shown by density functional theory. The vectorial transfer of protons, electrons, and hydrogen atoms allows for switching the mechanism of CO₂ reduction from a proton-coupled electron transfer pathway in aqueous solution to hydrogenation of CO₂ with a record high solar-to-methanol efficiency of 0.29%. The reported findings demonstrate a highly efficient, stable, and scalable wireless system for synthesis of methanol from CO₂ that could provide a viable path towards carbon neutrality and environmental sustainability.