Room-temperature synthesis of carnation-like ZnO@AgI hierarchical nanostructures assembled by AgI nanoparticles-decorated ZnO nanosheets with enhanced visible light photocatalytic activity

He Huang; Ni Huang; Zhonghua Wang; Guangqiang Xia; Ming Chen; Lingling He; Zhifang Tong; Chunguang Ren

doi:10.1016/j.jcis.2017.04.080

Room-temperature synthesis of carnation-like ZnO@AgI hierarchical nanostructures assembled by AgI nanoparticles-decorated ZnO nanosheets with enhanced visible light photocatalytic activity

J Colloid Interface Sci. 2017 Sep 15:502:77-88. doi: 10.1016/j.jcis.2017.04.080. Epub 2017 Apr 26.

Authors

He Huang¹, Ni Huang¹, Zhonghua Wang², Guangqiang Xia¹, Ming Chen¹, Lingling He¹, Zhifang Tong¹, Chunguang Ren³

Affiliations

¹ Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong, Sichuan 637002, PR China.
² Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong, Sichuan 637002, PR China. Electronic address: zhwangs@163.com.
³ Chinese Academy of Sciences, Shanghai Institute of Materia Medica, Yantai Branch, Yantai Institute of Materia Medica, Yantai, Shandong 264000, PR China.

PMID: 28478224
DOI: 10.1016/j.jcis.2017.04.080

Abstract

The preparation of highly efficient visible-light-driven photocatalyst for the photodegradation of organic pollutants has received much attention due to the increasing global energy crises and environmental pollution. In this study, carnation-like ZnO@AgI hierarchical nanostructures assembled by AgI nanoparticles-decorated ZnO nanosheets were successfully prepared via a room-temperature route. The as-prepared ZnO@AgI nanostructures exhibited highly efficient photocatalytic activity under visible light irradiation (λ>400nm). Under optimized AgI content, the ZnO@AgI-5% sample showed high photocatalytic activity, which was 25.7 and 1.5 times the activity of pure ZnO and pure AgI, respectively. Mechanism studies indicated that superoxide anion radicals (O₂^-) was the main reactive species in the photocatalytic process. The high photocatalytic activity of the ZnO@AgI nanostructures is attributed to the highly active AgI nanoparticles and the heterojunction between AgI nanoparticles and ZnO nanosheets. The heterojunction structure reduced the recombination of the photogenerated electron-hole pairs in the conduction band (CB) and valence band (VB) of AgI nanoparticles by transferring the electrons from the CB of AgI nanoparticles to the CB of ZnO nanosheets. The composite of ZnO and AgI not only improves photocatalytic efficiency but also reduces photocatalyst cost, which is beneficial for practical application.

Keywords: Environmental remediation; Hierarchical nanostructures; Photocatalytic activity; Pollutant degradation; Room-temperature synthesis; ZnO@AgI.