Molecule‐Driven Shape Control of Metal Co‐Catalysts for Selective CO 2 Conversion Photocatalysis

In photocatalysis of CO 2 conversion, metal co‐catalysts draw photo‐generated electrons from semiconductor components and act as reaction sites by adsorbing CO 2 and its intermediates. Optimization of the metal co‐catalyst structure is indispensable to improving the efficiency of the photocatalyst, which is currently not meeting performance requirements. By performing a series of experiments and simulations, we demonstrate the effect of selective particle shape control of metal co‐catalysts (Au, Ag, Cu and Pt) by the CO 2 induced gas ligands (CO 2 and CO) on photocatalytic CO 2 conversion activity and selectivity. Indeed, facet formation for adsorption of CO 2 and CO proves to be an effective way to improve the CO 2 conversion activity. In particular, proper interaction between the gas ligand and the metal co‐catalyst surface, realized by strengthening the metal‐CO 2 adsorption and weakening the metal‐CO adsorption, is identified as essential factor for increasing the CO 2 conversion activity. Pt and Cu, which exhibit relatively strong interaction with gas molecules, have the improved photocatalytic CO 2 conversion activity when grown under CO 2 . In contrast, Au and Ag, which exhibit relatively weak interaction with gas molecules, have the enhanced photocatalytic CO 2 conversion activity when grown under CO. This systematic understanding can be a guideline for controlling the metal co‐catalyst surface structure and will maximize the photocatalytic selectivity of the CO 2 conversion.