Fabrication of 1D/2D CdS/Ag:ZnIn2S4 heterostructure for greatly efficacious photocatalytic H2 production and wastewater purification

To improve the photocatalytic activities of photocatalysts, constructing heterojunction structures is considered as an effective measure. Herein, a series of the 1D (one dimensional)/2D (two dimensional) CdS/Ag-doped ZnIn 2 S 4 (denoted as CdS/Ag:ZIS) heterojunctions were constructed by growing 2D Ag:ZIS nanoplates on 1D CdS nanowires. Under visible light irradiation, the optimized CdS/Ag:ZIS shows H 2 production rate of as high as 2447.02 μmol g −1 h −1 , which has increased by 7.8 and 2.2 times compared to pure CdS and Ag:ZIS, respectively. Meanwhile, the degradation efficiency of methyl orange (MO) reaches 99.45% within 50 min. The enhanced photocatalytic activity is due to the improved absorption of visible light along with accelerated separation of photogenerated carriers, thanks to the formation of an intimate interface, suitable energy band alignment and abundant active sites. Furthermore, CdS/Ag:ZIS also exhibits high stability in both photocatalytic processes, with negligible decay over multiple photocatalytic cycles. Based on the results of density functional theory (DFT) and photoelectrochemical characterizations, a Z-scheme heterojunction is proposed, followed by in-depth studies of the charge transfer processes and the photocatalytic mechanisms.