Illustration of charge transfer in graphene-coated hexagonal ZnO photocatalysts using Kelvin probe force microscopy

doi:10.1039/c7ra12037k

	Illustration of charge transfer in graphene-coated hexagonal ZnO photocatalysts using Kelvin probe force microscopy
	Zhang, Yunlong 1; Zhang, Yuzhi ; Song, Lixin ; Su, Yang 1; Guo, Yunfeng 2; Wu, Lingnan ; Zhang, Tao
刊名	RSC ADVANCES
	2018
卷号	8 期号:2 页码:885
ISSN号	2046-2069
DOI	10.1039/c7ra12037k
英文摘要	A graphene coated hexagonal ZnO (HZO@Gr) with enhanced activity in photocatalysis was synthesized. However, the photoinduced charge transfer behavior and the beneficial role of graphene in promoting photocatalytic reactions have not been sufficiently investigated experimentally. In this paper, the surface potentials of the +/-(0001)-polar plane of HZO (Zn-polar plane and O-polar plane), graphene, graphene/Zn-polar plane and graphene/O-polar plane were measured using Kelvin probe force microscopy (KPFM). On the basis of the KPFM results, the respective Fermi levels were calculated and the internal electric field (IEF) of HZO was confirmed. Taking the IEF of HZO into consideration, the three-dimensional band diagrams of the HZO@Gr composites in methyl blue (MB) solution in the dark and under UV-visible irradiation after equilibrium were proposed. Accordingly, it is found that there could emerge different interactions between graphene and HZO at the +/-(0001)-polar plane of HZO. Furthermore, the photogenerated holes and electrons tend to migrate to opposite directions. With the participation of graphene and IEF, the composites show a decrease in possibility of charge recombination. As a result, the active groups, namely -OH and -O-2(center dot) radicals, could be mainly generated at/near the O-polar plane and Zn-polar plane, respectively. This work can serve as a supplemental explanation of the charge transfer during the photocatalytic process at the polar ZnO/graphene composite surface.
学科主题	Chemistry, Multidisciplinary
出版者	ROYAL SOC CHEMISTRY
WOS记录号	WOS:000419347900033
内容类型	期刊论文
源URL	[http://ir.sic.ac.cn/handle/331005/24601]
专题	中国科学院上海硅酸盐研究所
作者单位	1.Chinese Acad Sci, Shanghai Inst Ceram, Key Lab Inorgan Coating Mat, 1295 Dingxi Rd, Shanghai 200050, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Shanghai Univ, Sch Mat Sci & Engn, 99 Shangda Rd, Shanghai 200444, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Yunlong,Zhang, Yuzhi,Song, Lixin,et al. Illustration of charge transfer in graphene-coated hexagonal ZnO photocatalysts using Kelvin probe force microscopy[J]. RSC ADVANCES,2018,8(2):885, 894.
APA	Zhang, Yunlong.,Zhang, Yuzhi.,Song, Lixin.,Su, Yang.,Guo, Yunfeng.,...&Zhang, Tao.(2018).Illustration of charge transfer in graphene-coated hexagonal ZnO photocatalysts using Kelvin probe force microscopy.RSC ADVANCES,8(2),885.
MLA	Zhang, Yunlong,et al."Illustration of charge transfer in graphene-coated hexagonal ZnO photocatalysts using Kelvin probe force microscopy".RSC ADVANCES 8.2(2018):885.