Introducing defect engineering into ZnO/ZnS heterojunction photocatalysts is an effective method to simultaneously improve their visible light performance and photocatalytic efficiency. Herein, we innovatively synthesized defect enriched ZnO/ZnS heterostructure photocatalyst through a hydrozincite (Zn5(OH)6(CO3)2) intermediate deriving reaction. The mechanism analysis shows that there are interstitial Zn and Zn vacancies in the hydrozincite derived ZnO, while S vacancies, interstitial S and Zn vacancies are formed in ZnS components after calcination. These specific defects states endow visible light response ability to both ZnO and ZnS components in the ZnO/ZnS photocatalysts. Under visible light irradiation, the photocatalytic hydrogen evolution rate of ZnO/ZnS reaches 11.68 mmol h-1 g-1, and under simulated sunlight irradiation, the best photocatalytic hydrogen evolution rate can reach 27.94 mmol h-1 g-1, which is much higher than most of previous reports. The analysis of energy band structure and photodeposition shows that the photocatalytic reduction sites are mainly on ZnS, and the photocatalytic reaction mainly follows the typical Z-type mechanism. This work presents a simple and low-cost method for the preparation of defects enriched ZnO/ZnS based photocatalytic materials with high photocatalytic activity and stability.

Citation

Yaqing Zhi,Yuan Yi, Chenxi Deng,Qiao Zhang,Siyuan Yang,* Feng Peng*. Defect enriched ZnO/ZnS heterostructures derived from hydrozincite intermediates for hydrogen evolution under visible light, 2022, ChemSusChem, doi.org/10.1002/cssc.202200860