Site‐Sensitive Selective CO2 Photoreduction to CO over Gold Nanoparticles

Abstract We demonstrate a new case of materials–gene engineering to precisely design photocatalysts with the prescribed properties. Based on theoretical calculations, a phase‐doping strategy was proposed to regulate the pathways of CO 2 conversion over Au nanoparticles (NPs) loaded TiO 2 photocatalysts. As a result, the thermodynamic bottleneck of CO 2 ‐to‐CO conversion is successfully unlocked by the incorporation of stable twinning crystal planes into face‐centered cubic ( fcc ) phase Au NPs. Compared to bare pristine TiO 2 , the activity results showed that the loading of regular fcc ‐Au NPs raised the CO production by 18‐fold but suppressed the selectivity from 84 % to 75 %, whereas Au NPs with twinning (110) and (100) facets boosted the activity by nearly 40‐fold and established near unity CO selectivity. This enhancement is shown to originate from a beneficial shift in the surface reactive site energetics arising at the twinned stacking fault, whereby both the CO reaction energy and desorption energy were significantly reduced.