Boosted Hydrogen-Evolution Kinetics Over Particulate Lanthanum and Rhodium-Doped Strontium Titanate Photocatalysts Modified with Phosphonate Groups

Yosuke Kageshima; Toshiki Kawanishi; Daisuke Saeki; Katsuya Teshima; Kazunari Domen; Hiromasa Nishikiori

doi:10.1002/anie.202011705

Boosted Hydrogen-Evolution Kinetics Over Particulate Lanthanum and Rhodium-Doped Strontium Titanate Photocatalysts Modified with Phosphonate Groups

Angew Chem Int Ed Engl. 2021 Feb 15;60(7):3654-3660. doi: 10.1002/anie.202011705. Epub 2020 Dec 14.

Authors

Yosuke Kageshima^{1

2}, Toshiki Kawanishi¹, Daisuke Saeki^{1

2}, Katsuya Teshima^{1

2}, Kazunari Domen^{2

3}, Hiromasa Nishikiori^{1

2}

Affiliations

¹ Department of Materials Chemistry, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan.
² Research Initiative for Supra-Materials (RISM), Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan.
³ Office of University Professors, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.

PMID: 33166019
DOI: 10.1002/anie.202011705

Abstract

Phosphonate groups loaded on the surface of the visible-light-responsive photocatalyst Ru-loaded La,Rh-doped SrTiO₃ (Ru/La,Rh:STO) via a silane-coupling treatment enhance the photocatalytic activity of this material during the hydrogen evolution reaction. Surface modification with an alkylsilane phosphonate accelerates the supply of reactants to active sites and is much more effective at improving the photocatalytic activity than the utilization of a phosphate-buffered electrolyte as a reaction solution. In contrast, the incorporation of amine, sulfonate, and propyl groups does not improve the activity. The effects of these functional groups introduced via silane coupling on the reaction kinetics of hydrogen evolution are evaluated separately from the oxidative reaction using electrochemical methods. It was also demonstrated that the present alkylsilane phosphonate modification increases the photocatalytic activity even under a low photon flux.

Keywords: hydrogen evolution; phosphonate groups; photocatalysis; reaction kinetics; silane coupling.

Abstract

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