Unique hole-accepting carbon-dots promoting selective carbon dioxide reduction nearly 100% to methanol by pure water.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32439875.
- Also identified by DOI 10.1038/s41467-020-16227-3 and PMC identifier 7242399.
- 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
Solar-driven CO<sub>2</sub> reduction by abundant water to alcohols can supply sustainable liquid fuels and alleviate global warming. However, the sluggish water oxidation reaction has been hardly reported to be efficient and selective in CO<sub>2</sub> conversion due to fast charge recombination. Here, using transient absorption spectroscopy, we demonstrate that microwave-synthesised carbon-dots (<sup>m</sup>CD) possess unique hole-accepting nature, prolonging the electron lifetime (t<sub>50%</sub>) of carbon nitride (CN) by six folds, favouring a six-electron product. <sup>m</sup>CD-decorated CN stably produces stoichiometric oxygen and methanol from water and CO<sub>2</sub> with nearly 100% selectivity to methanol and internal quantum efficiency of 2.1% in the visible region, further confirmed by isotopic labelling. Such <sup>m</sup>CD rapidly extracts holes from CN and prevents the surface adsorption of methanol, favourably oxidising water over methanol and enhancing the selective CO<sub>2</sub> reduction to alcohols. This work provides a unique strategy for efficient and highly selective CO<sub>2</sub> reduction by water to high-value chemicals.