Efficient photocatalytic degradation of toxic Alizarin yellow R dye from industrial wastewater using biosynthesized Fe nanoparticle and study of factors affecting the degradation rate.

Development of highly robust and solar-light-responsive photocatalysts for the disposal of organic dyes from wastewater is a matter of great significance in order to solve the problems of water pollution. Solar-driven photocatalytic degradation of dyes is considered as a quite efficient, sustainable and cost-effective approach as it involved the inexhaustible and renewable source of energy. In photocatalytic processes, the generation of electron-hole pairs at the surface of the photocatalyst is accomplished by harvesting solar energy. The electron-hole pairs are converted into •OH radicals that are responsible for the degradation of dyes. Herein, we reported the synthesis of nanosized iron (FeNPs) using the aqueous fruit extract of Actinidia chinensis as a reducing as well as the stabilizing agent. The structure and morphology of synthesized nanoparticles were characterized using various advanced techniques. The TEM micrographs showed that the synthesized FeNPs was predominantly cubic and rod-shaped having the size in the range of 91.78-107 nm. The as-prepared FeNPs were acted as effective photocatalysts and their photocatalytic activity evaluated against alizarin yellow R (AYR) dye. The effect of different reaction conditions such as temperature, pH, time and catalyst loading on photocatalytic degradation of AYR dye was investigated under sunlight irradiation. The FeNPs showed promising photocatalytic activity and up to 93.7% of the dye was degraded in 42 h. The kinetics parameter of the reaction was also evaluated which showed that the photocatalytic degradation of AYR dye followed the pseudo-first-order reaction. In terms of better degradation, the role of FeNPs might be extended for the treatment of different organic dyes from wastewater.