Solar-driven water oxidation and decoupled hydrogen production mediated by an electron-coupled-proton buffer

Bloor, L. G., Solarska, R., Bienkowski, K., Kulesza, P. J., Augustynski, J., Symes, M. D. and Cronin, L. (2016) Solar-driven water oxidation and decoupled hydrogen production mediated by an electron-coupled-proton buffer. Journal of the American Chemical Society, 138(21), pp. 6707-6710. (doi: 10.1021/jacs.6b03187) (PMID:27159121) (PMCID:PMC5033397)

Abstract

Solar-to-hydrogen photoelectrochemical cells (PECs) have been proposed as a means of converting sunlight into H2 fuel. However, in traditional PECs, the oxygen evolution reaction and the hydrogen evolution reaction are coupled, and so the rate of both of these is limited by the photocurrents that can be generated from the solar flux. This in turn leads to slow rates of gas evolution that favor crossover of H2 into the O2 stream and vice versa, even through ostensibly impermeable membranes such as Nafion. Herein, we show that the use of the electron-coupled-proton buffer (ECPB) H3PMo12O40 allows solar-driven O2 evolution from water to proceed at rates of over 1 mA cm–2 on WO3 photoanodes without the need for any additional electrochemical bias. No H2 is produced in the PEC, and instead H3PMo12O40 is reduced to H5PMo12O40. If the reduced ECPB is subjected to a separate electrochemical reoxidation, then H2 is produced with full overall Faradaic efficiency.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Symes, Professor Mark and Bloor, Dr Leanne and Cronin, Professor Lee
• Authors: Bloor, L. G., Solarska, R., Bienkowski, K., Kulesza, P. J., Augustynski, J., Symes, M. D., and Cronin, L.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of the American Chemical Society
• Publisher: American Chemical Society
• ISSN: 0002-7863
• ISSN (Online): 1520-5126
• Published Online: 09 May 2016

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
57739	1	Programmable Molecular Metal Oxides (PMMOs) - From Fundamentals to Application	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/J015156/1	CHEM - CHEMISTRY
64661	1	Programmable 'Digital' Synthesis for Discovery and Scale-up of Molecules, Clusters and Nanomaterials	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/L023652/1	CHEM - CHEMISTRY
56282	1	Innovative Manufacturing Research Centre for Continuous Manufacturing and Crystallisation (CMAC)	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/I033459/1	CHEM - CHEMISTRY
61602	1	Energy and the Physical Sciences: Hydrogen Production using a Proton Electron Buffer	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/K023004/1	CHEM - CHEMISTRY
59945	1	Microscale Chemically Reactive Electronic Agents	Leroy Cronin	European Commission (EC)	FP7 ICT MICRE31	CHEM - CHEMISTRY