Efficient degradation of azo dye pollutants on Zn doped SnO2 photocatalyst under sunlight irradiation: Performance, mechanism and toxicity evaluation

Abstract

Pollution of the environment becomes a serious issue to the living beings in which the water pollution requires immediate remediation. Herein, pure SnO2 and different concentrations of Zn doped SnO2 nanoparticles (NPs) were lucratively synthesized by co-precipitation approach and the structural, optical, morphological properties of NPs were studied using FT-IR, XRD, FE-SEM, TEM, UV–Vis and Raman Spectroscopy techniques. The NPs were used as the photocatalyst for the degradation of MB-A (Methyl Blue) and MB (Methylene Blue) dyes as textile pollutants under sunlight irradiation. The high degradation photodegradation efficiency of 98.2% and 92.1% were achieved for MB-A and MB dyes, respectively for the 5 wt% of Zn doped SnO2. The rate constant value of 5 wt% Zn doped SnO2 was around four times higher than that of pure SnO2 for degradation of both textile dyes. The enhanced photocatalytic activity might be the Zn doping effect where the doped Zn plays an essential role in reducing bandgap and increasing the hole and hydroxyl radical generation which promotes the activity and stability of the photocatalyst. In addition, antimicrobial activity and seed germination was studied for the doped samples. As a result, a cell death investigation demonstrated non-toxicity and pollutant removal.