Achievement of visible-light-driven Z-scheme overall water splitting using barium-modified Ta3N5 as a H2-evolving photocatalyst

Yu Qi; Shanshan Chen; Mingrun Li; Qian Ding; Zheng Li; Junyan Cui; Beibei Dong; Fuxiang Zhang; Can Li

doi:10.1039/c6sc02750d

Achievement of visible-light-driven Z-scheme overall water splitting using barium-modified Ta₃N₅ as a H₂-evolving photocatalyst

Chem Sci. 2017 Jan 1;8(1):437-443. doi: 10.1039/c6sc02750d. Epub 2016 Aug 18.

Authors

Yu Qi^{1

2}, Shanshan Chen¹, Mingrun Li¹, Qian Ding^{1

2}, Zheng Li^{1

2}, Junyan Cui^{1

3}, Beibei Dong^{1

2}, Fuxiang Zhang¹, Can Li¹

Affiliations

¹ State Key Laboratory of Catalysis , iChEM , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian National Laboratory for Clean Energy , Dalian , 116023 , China . Email: fxzhang@dicp.ac.cn ; Email: canli@dicp.ac.cn ; http://canli.dicp.ac.cn.
² University of Chinese Academy of Sciences , Beijing 100049 , China.
³ Key Laboratory of Surface and Interface Chemistry of Jilin Province , College of Chemistry , Jilin University , Changchun 130021 , China.

Abstract

Ta₃N₅ is one of the most promising photocatalyst candidates for solar water splitting, but it still remains challenging to achieve overall water splitting via Ta₃N₅-based photocatalysts regardless of whether it uses a one step or two step method. Here we will address the relatively poor photocatalytic proton reduction of Ta₃N₅ with an effort for the promotion of charge separation via barium modification. One-pot nitridation of barium nitrate-impregnated Ta₂O₅ precursor was adopted here for the synthesis of Ta₃N₅ accompanied with the creation of a Ta₃N₅/BaTaO₂N heterostructure and surface passivation. Due to the synergetic effect of the improved interfacial charge separation and the decreased defect density, the photocatalytic H₂ evolution rate of barium-modified Ta₃N₅ is effectively promoted. Encouraged by this, a visible-light-driven Z-scheme overall water splitting system was successfully constructed by using the barium-modified Ta₃N₅ as a H₂-evolving photocatalyst, together with a PtO _x /WO₃ and IO₃^-/I^- pair as an O₂-evolving photocatalyst and a redox mediator, respectively.