Hydrogen evolution from water using Ag(x)Cu(1-x)GaSe2 photocathodes under visible light

Li Zhang; Tsutomu Minegishi; Jun Kubota; Kazunari Domen

doi:10.1039/c3cp54590c

Hydrogen evolution from water using Ag(x)Cu(1-x)GaSe2 photocathodes under visible light

Phys Chem Chem Phys. 2014 Apr 7;16(13):6167-74. doi: 10.1039/c3cp54590c.

Authors

Li Zhang¹, Tsutomu Minegishi, Jun Kubota, Kazunari Domen

Affiliation

¹ Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. domen@chemsys.t.u-tokyo.ac.jp.

PMID: 24562096
DOI: 10.1039/c3cp54590c

Abstract

Photoelectrochemical (PEC) water splitting using CuGaSe2 (CGSe) thin film photocathodes modified by partial substitution of Cu with Ag was investigated. The AgxCu1-xGaSe2 (ACGSe) thin films were deposited onto Mo-coated soda-lime glass substrates by means of co-evaporation using a molecular beam epitaxy (MBE) system. The valence band maximum (VBM) potential of ACGSe is deeper than that of CGSe, and its grain size is greatly increased compared to that of CGSe. A Pt and CdS modified ACGSe electrode (Pt/CdS/ACGSe) with a Ag/(Cu + Ag) ratio of about 5% showed a cathodic photocurrent of 8.1 mA cm(-2) at 0 VRHE and an onset potential of 0.70 VRHE (defined as a cathodic photocurrent of 0.05 mA cm(-2)) under simulated sunlight in a 0.1 M Na2SO4 solution (pH 9.5). Moreover, Pt/CdS/ACGSe exhibited a stable cathodic photocurrent for over 55 h, with no clear decrease.