Assembly of large-area reduced graphene oxide films for the construction of Z-scheme over single-crystal porous Bi5O7I nanosheets

Min Wang; Qiming Wang; Jinglin Li; Haikun Zhang; Wenjie Zhang; Binghui Xu; Peizhi Guo; Zhengbo Jiao; Xiu Song Zhao

doi:10.1016/j.jcis.2019.05.107

Assembly of large-area reduced graphene oxide films for the construction of Z-scheme over single-crystal porous Bi₅O₇I nanosheets

J Colloid Interface Sci. 2019 Sep 15:552:651-658. doi: 10.1016/j.jcis.2019.05.107. Epub 2019 May 31.

Authors

Min Wang¹, Qiming Wang¹, Jinglin Li¹, Haikun Zhang¹, Wenjie Zhang¹, Binghui Xu¹, Peizhi Guo¹, Zhengbo Jiao², Xiu Song Zhao³

Affiliations

¹ Institute of Materials for Energy and Environment, and College of Material Science and Engineering, Qingdao University, Qingdao 266071, China.
² Institute of Materials for Energy and Environment, and College of Material Science and Engineering, Qingdao University, Qingdao 266071, China. Electronic address: jiaozhb@qdu.edu.cn.
³ Institute of Materials for Energy and Environment, and College of Material Science and Engineering, Qingdao University, Qingdao 266071, China; School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.

PMID: 31173993
DOI: 10.1016/j.jcis.2019.05.107

Abstract

In this work, we have firstly achieved the construction of bismuth oxyiodide (Bi₅O₇I)/reduced graphene oxide (rGO)/ZnO Z-scheme photoelectrochemical (PEC) system without backward reactions through loading large-area ZnO quantum dots (QDs)/rGO films on Bi₅O₇I nanosheets. Single-crystal porous Bi₅O₇I nanosheets with numerous oxygen vacancies (OVs) were firstly fabricated through the calcination of BiOI in reductive glycols. The single-crystal facilitates charge transport, nanoporous structure promotes light absorption and OVs improves charge separation efficiency. As a result, single-crystal porous Bi₅O₇I nanosheets with OVs exhibited higher PEC performance than other morphologies reported before. Moreover, The PEC activity of Bi₅O₇I can be further enhanced through loading large-area ZnO QDs/rGO films to construct a pure Z-scheme charge transfer system, which not only achieves efficient separation of electron-hole pairs but also retains its excellent redox ability. To the best of our knowledge, the photocurrent density of Bi₅O₇I/rGO/ZnO heterostructures is the highest among Bi₅O₇I-based samples. For comparison, an opposite Z-scheme model has also been built up by replacing Bi₅O₇I with WO₃, in which the photocurrent density decreased conversely. Therefore, it can be known that a pure Z-scheme system without backward reactions can be successfully prepared through loading ZnO QDs/rGO films on photoelectrodes.

Keywords: Bi(5)O(7)I; Photoelectrochemical; Self-assembly; Z-scheme; rGO.