Superior solar-to-hydrogen energy conversion efficiency by visible light-driven hydrogen production via highly reduced Ti2+/Ti3+ states in a blue titanium dioxide photocatalyst. Issue 18 (17th August 2018)

• Record Type: Journal Article
• Authors: De Silva, Nuwan Lakshitha; Jayasundera, A. C. A.; Folger, A.; Kasian, O.; Zhang, S.; Yan, Chang-Feng; Scheu, C.; Bandara, J.
• Is Part Of: Catalysis science & technology. Volume 8:Issue 18(2018)
• Page Start: 4657
• Page End: 4664
• Publication Date: 2018-08-17
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c8cy01212a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : A catalytic hydrogen production system was developed with TiO2 that contains Ti 3+ /Ti 2+ reduced states which act as both visible and IR light harvesting components as well as the catalytic site. Abstract : Photocatalytic water splitting is one of the most important renewable paths and a reliable hydrogen production system. In most successful molecular and supramolecular biomimetic hydrogen production methods, a photosensitizer and a catalyst were constructed where the photoexcited electron in the photosensitizer is transferred either inter- or intramolecularly to the catalytic centre. Similar to supramolecular complexes in a photocatalytic hydrogen production scheme, here we develop a redox system that contains Ti 3+ /Ti 2+ reduced states in TiO2 which act as both visible light harvesting components and the catalytic sites for the catalytic hydrogen production with visible-near infrared photons. The Ti 3+ /Ti 2+ states in TiO2 produce hydrogen from pure water with a solar-to-hydrogen energy conversion efficiency of 0.89% and a quantum yield of 43% at 655 nm. The mechanism of hydrogen production by the Ti 3+ /Ti 2+ reduced states in TiO2 involves the initial generation of highly air stable and highly reduced Ti 3+ and Ti 2+ states in TiO2 by the formation of an AlOOH layer surrounding the anatase and rutile particles. Once Ti 3+ and Ti 2+ states are generated, these states are continuously self-generated via absorption of visible-near infrared radiation where hydrogen is produced by the transfer of electrons from Ti 3+ /Ti 2+ to H + .