Unique hole-accepting carbon-dots promoting selective carbon dioxide reduction nearly 100% to methanol by pure water

Yiou Wang; Xu Liu; Xiaoyu Han; Robert Godin; Jialu Chen; Wuzong Zhou; Chaoran Jiang; Jamie F Thompson; K Bayazit Mustafa; Stephen A Shevlin; James R Durrant; Zhengxiao Guo; Junwang Tang

doi:10.1038/s41467-020-16227-3

Unique hole-accepting carbon-dots promoting selective carbon dioxide reduction nearly 100% to methanol by pure water

Nat Commun. 2020 May 21;11(1):2531. doi: 10.1038/s41467-020-16227-3.

Authors

Yiou Wang^#^{1

2}, Xu Liu^#¹, Xiaoyu Han^{3

4}, Robert Godin^{5

6}, Jialu Chen⁷, Wuzong Zhou⁷, Chaoran Jiang¹, Jamie F Thompson⁸, K Bayazit Mustafa^{1

9}, Stephen A Shevlin³, James R Durrant⁸, Zhengxiao Guo^{10

11

12

13}, Junwang Tang¹⁴

Affiliations

¹ Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
² Chair for Photonics and Optoelectronics, Nano-Institute Munich, Ludwig-Maximilians-Universität München, Königinstr. 10, 80539, Munich, Germany.
³ Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
⁴ Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
⁵ Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. robert.godin@ubc.ca.
⁶ Department of Chemistry, The University of British Columbia, Kelowna, BC, V1V 1V7, Canada. robert.godin@ubc.ca.
⁷ School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK.
⁸ Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK.
⁹ Nanotechnology Research and Application Center, Sabancı University, Orta Mahallesi, Üniversite Cd. No: 27, 34956, Tuzla/İstanbul, Turkey.
¹⁰ Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK. zxguo@hku.hk.
¹¹ Department of Chemistry, HKU-CAS Joint Laboratory on New Materials, The University of Hong Kong, Hong Kong, China. zxguo@hku.hk.
¹² Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. zxguo@hku.hk.
¹³ HKU Zhejiang Institute of Research and Innovation, The University of Hong Kong, Hangzhou, China. zxguo@hku.hk.
¹⁴ Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK. junwang.tang@ucl.ac.uk.

^# Contributed equally.

Abstract

Solar-driven CO₂ 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 CO₂ conversion due to fast charge recombination. Here, using transient absorption spectroscopy, we demonstrate that microwave-synthesised carbon-dots (^mCD) possess unique hole-accepting nature, prolonging the electron lifetime (t_50%) of carbon nitride (CN) by six folds, favouring a six-electron product. ^mCD-decorated CN stably produces stoichiometric oxygen and methanol from water and CO₂ with nearly 100% selectivity to methanol and internal quantum efficiency of 2.1% in the visible region, further confirmed by isotopic labelling. Such ^mCD rapidly extracts holes from CN and prevents the surface adsorption of methanol, favourably oxidising water over methanol and enhancing the selective CO₂ reduction to alcohols. This work provides a unique strategy for efficient and highly selective CO₂ reduction by water to high-value chemicals.

Abstract

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