Durable hydrogen evolution from water driven by sunlight using (Ag,Cu)GaSe2 photocathodes modified with CdS and CuGa3Se5

Li Zhang; Tsutomu Minegishi; Mamiko Nakabayashi; Yohichi Suzuki; Kazuhiko Seki; Naoya Shibata; Jun Kubota; Kazunari Domen

doi:10.1039/c4sc02346c

Durable hydrogen evolution from water driven by sunlight using (Ag,Cu)GaSe₂ photocathodes modified with CdS and CuGa₃Se₅

Chem Sci. 2015 Feb 1;6(2):894-901. doi: 10.1039/c4sc02346c. Epub 2014 Sep 4.

Authors

Li Zhang¹, Tsutomu Minegishi¹, Mamiko Nakabayashi², Yohichi Suzuki³, Kazuhiko Seki³, Naoya Shibata², Jun Kubota¹, Kazunari Domen¹

Affiliations

¹ Department of Chemical System Engineering , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-8656 , Japan . Email: domen@chemsys.t.u-tokyo.ac.jp ; ; Tel: +81-3-5841-1652.
² Institute of Engineering Innovation , The University of Tokyo , 2-11-16 Yayoi , Bunkyo-ku , Tokyo 113-8656 , Japan.
³ NRI , National Institute of Advanced Industrial Science and Technology (AIST) , AIST Tsukuba Central 5, Higashi 1-1-1 , Tsukuba , Ibaraki 305-8565 , Japan.

Abstract

The photoelectrochemical properties of (Ag,Cu)GaSe₂ (ACGSe) modified by deposition of CdS and CuGa₃Se₅ layers were investigated. The CdS and CuGa₃Se₅ layers formed p-n junctions with an appropriate band diagram on the surface of the electrode and they clearly increased the cathodic photocurrent and onset potential. The Pt, CdS, and CuGa₃Se₅ modified ACGSe (Pt/CdS/CuGa₃Se₅/ACGSe) with an appropriate thickness of CuGa₃Se₅ layers (ca. 100 nm) showed a cathodic photocurrent of 8.79 mA cm^-2 at 0 V_RHE and an onset potential of 0.62 V_RHE (defined as cathodic photocurrent of 1.0 mA cm^-2) under simulated sunlight irradiation in 0.1 M Na₂HPO₄ (pH 10). Pt/CdS/CuGa₃Se₅/ACGSe showed durable cathodic current under the observed reaction conditions and hydrogen was evolved for about 20 days.