Inhibition of photocorrosion and photoactivity enhancement for ZnO via specific hollow ZnO core/ZnS shell structure

Hollow ZnO core/ZnS shell structure (ZnO/ZnS HCSS) has been successfully synthesized via a microwave-assisted hydrothermal approach. It is found that such a ZnO/ZnS HCSS exhibits higher photocatalytic activity than pure ZnO and ZnS toward the liquid-phase degradation of methyl orange (MO) under UV irradiation. What is more noteworthy, it is also demonstrated that ZnO/ZnS HCSS photocatalyst overcomes the photocorrosion in comparison to pristine ZnO by mean of cycling tests toward MO. The detailed degradation process of MO over ZnO/ZnS HCSS is investigated by liquid chromatography mass spectrometry method. And then, the roles of active species in the photocatalytic process are discussed by using different types of active species scavengers. Meanwhile, combined with the electron spin resonance and photocurrent test, the degradation mechanism of the photocatalysts is proposed. It is hoped that the work could provide valuable information on the design of specific structure materials with more excellent properties and set the foundation for the further industrial application. (C) 2014 Elsevier B.V. All rights reserved.