摘要：The present work deals with the photocatalytic removal of Cr(VI) by zinc oxide particles. Cr(VI) removal capacity of 494.4 mg/g, 369.27 mg/g, and 355.59 mg/g was noted in sunlight, fluorescent, and dark conditions respectively at optimized parameters (pH: 5.0, initial Cr(VI) concentration: 50 mg/L, particle dosage: 10 mg/L, contact time: 60 min). A Langmuir isotherm model and pseudo first order kinetics were observed. The aggregation of Cr(VI) interacted ZnO particles was observed by dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results suggest the photon‐assisted reduction of Cr(VI) to Cr(III) on the ZnO particle. The EDX, FTIR, and EELS indicated Cr(VI) removal by an adsorption‐coupled reduction mechanism. Lower aggregation observed in the sunlight condition favoured enhanced Cr(VI) sorption compared to that in fluorescent light. Fourier transform infrared spectroscopy (FTIR) and energy‐dispersive X‐ray spectroscopy (EDX) confirmed the interaction of Cr(VI) on the particle surface and the electron energy loss spectroscopy (EELS) confirmed its subsequent reduction to Cr(III). The applicability of the process was studied with Cr(VI)–Cr(III) binary mixture and the multi–metal solutions.
