Boosting thermo-photocatalytic CO(2) conversion activity by using photosynthesis-inspired electron-proton-transfer mediators

Natural photosynthesis proceeded by sequential water splitting and CO(2) reduction reactions is an efficient strategy for CO(2) conversion. Here, mimicking photosynthesis to boost CO(2)-to-CO conversion is achieved by using plasmonic Bi as an electron-proton-transfer mediator. Electroreduction of H(2)O with a Bi electrode simultaneously produces O(2) and hydrogen-stored Bi (Bi-H(x)). The obtained Bi-H(x) is subsequently used to generate electron-proton pairs under light irradiation to reduce CO(2) to CO; meanwhile, Bi-H(x) recovers to Bi, completing the catalytic cycle. This two-step strategy avoids O(2) separation and enables a CO production efficiency of 283.8 μmol g(−1) h(−1) without sacrificial reagents and cocatalysts, which is 9 times that on pristine Bi in H(2) gas. Theoretical/experimental studies confirm that such excellent activity is attributed to the formed Bi-H(x) intermediate that improves charge separation and reduces reaction barriers in CO(2) reduction.