Surface disorder engineering in ZnCdS for cocatalyst free visible light driven hydrogen production

Abstract

Metal chalcogenide solid solution, especially ZnCdS, has been intensively investigated in photocatalytic H2 generation due to their cost-effective synthetic procedure and adjustable band structures. In this work, we report on the defect engineering of ZnCdS with surface disorder layer by simple room temperature Li-ethylenediamine (Li-EDA) treatment. Experimental results confirm the formation of unusual Zn and S dual vacancies, where rich S vacancies (VS) served as electron trapping sites, meanwhile Zn vacancies (VZn) served as hole trapping sites. The refined structure significantly facilitates the photo charge carrier transfer and improves photocatalytic properties of ZnCdS. The disordered ZnCdS shows a highest photocatalytic H2 production rate of 33.6 mmol·g−1·h−1 under visible light with superior photocatalytic stabilities, which is 7.3 times higher than pristine ZnCdS and 7 times of Pt (1 wt.%) loaded ZnCdS.