Highly Active GaN-Stabilized Ta3 N5 Thin-Film Photoanode for Solar Water Oxidation

Miao Zhong; Takashi Hisatomi; Yutaka Sasaki; Sayaka Suzuki; Katsuya Teshima; Mamiko Nakabayashi; Naoya Shibata; Hiroshi Nishiyama; Masao Katayama; Taro Yamada; Kazunari Domen

doi:10.1002/anie.201700117

Highly Active GaN-Stabilized Ta₃ N₅ Thin-Film Photoanode for Solar Water Oxidation

Angew Chem Int Ed Engl. 2017 Apr 18;56(17):4739-4743. doi: 10.1002/anie.201700117. Epub 2017 Mar 21.

Authors

Miao Zhong^{1

2}, Takashi Hisatomi^{1

2}, Yutaka Sasaki^{1

2}, Sayaka Suzuki³, Katsuya Teshima³, Mamiko Nakabayashi^{1

2}, Naoya Shibata^{1

2}, Hiroshi Nishiyama^{1

2}, Masao Katayama^{1

2}, Taro Yamada^{1

2}, Kazunari Domen^{1

2}

Affiliations

¹ School of Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
² Japan Technological Research Association of Artificial Photosynthetic Chemical Process, 2-11-9 Iwamotocho, Chiyoda-ku, Tokyo, 101-0032, Japan.
³ Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan.

PMID: 28323376
DOI: 10.1002/anie.201700117

Abstract

Ta₃ N₅ is a very promising photocatalyst for solar water splitting because of its wide spectrum solar energy utilization up to 600 nm and suitable energy band position straddling the water splitting redox reactions. However, its development has long been impeded by poor compatibility with electrolytes. Herein, we demonstrate a simple sputtering-nitridation process to fabricate high-performance Ta₃ N₅ film photoanodes owing to successful synthesis of the vital TaO_δ precursors. An effective GaN coating strategy is developed to remarkably stabilize Ta₃ N₅ by forming a crystalline nitride-on-nitride structure with an improved nitride/electrolyte interface. A stable, high photocurrent density of 8 mA cm^-2 was obtained with a CoPi/GaN/Ta₃ N₅ photoanode at 1.2 V_RHE under simulated sunlight, with O₂ and H₂ generated at a Faraday efficiency of unity over 12 h. Our vapor-phase deposition method can be used to fabricate high-performance (oxy)nitrides for practical photoelectrochemical applications.

Keywords: electrochemistry; photoanodes; photochemistry; solar energy conversion; water splitting.

Publication types

Research Support, Non-U.S. Gov't