Boosting thermo-photocatalytic CO<sub>2</sub> conversion activity by using photosynthesis-inspired electron-proton-transfer mediators.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33402672.
- Also identified by DOI 10.1038/s41467-020-20444-1 and PMC identifier 7785748.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Natural photosynthesis proceeded by sequential water splitting and CO<sub>2</sub> reduction reactions is an efficient strategy for CO<sub>2</sub> conversion. Here, mimicking photosynthesis to boost CO<sub>2</sub>-to-CO conversion is achieved by using plasmonic Bi as an electron-proton-transfer mediator. Electroreduction of H<sub>2</sub>O with a Bi electrode simultaneously produces O<sub>2</sub> and hydrogen-stored Bi (Bi-H<sub>x</sub>). The obtained Bi-H<sub>x</sub> is subsequently used to generate electron-proton pairs under light irradiation to reduce CO<sub>2</sub> to CO; meanwhile, Bi-H<sub>x</sub> recovers to Bi, completing the catalytic cycle. This two-step strategy avoids O<sub>2</sub> separation and enables a CO production efficiency of 283.8 μmol g<sup>-1</sup> h<sup>-1</sup> without sacrificial reagents and cocatalysts, which is 9 times that on pristine Bi in H<sub>2</sub> gas. Theoretical/experimental studies confirm that such excellent activity is attributed to the formed Bi-H<sub>x</sub> intermediate that improves charge separation and reduces reaction barriers in CO<sub>2</sub> reduction.