CdS@CuInS2 nanocomposites for enhanced photocatalytic activity under visible light irradiation

Abstract

Copper indium sulfide (CuInS2) and CuInS2 modified with different percentages of CdS (10% CdS@CuInS2, 20% CdS@CuInS2, and 30% CdS@CuInS2) were successfully synthesized, as confirmed by structural, optical, and morphological characterization. The photocatalytic performance of the CuInS2 and CdS@CuInS2 composites was evaluated by degrading brilliant green (BG) dye and converting 4-nitrophenol under visible light irradiation. Amongst the synthesized photocatalysts, 30% CdS@CuInS2 exhibited the highest photocatalytic activity, degrading 96.8% of BG within 5 h. The active species involved in the degradation processes were investigated by performing degradation experiments in the presence of suitable trapping agents for superoxide radical ions (O2•−), hydroxyl radicals (•OH), and valence band holes (h+). It was found that O2•− is the main active species in the photocatalytic degradation of BG by CdS@CuInS2. Moreover, the photocatalytic conversion of 4-nitrophenol was also enhanced up to 95.5% under visible light irradiation, and h+ is the main active species involved in the conversion. This work opens new avenues for the development of highly efficient photocatalysts for practical wastewater remediation.