Photocatalytic degradation of Congo Red under UV irradiation by zero valent iron nano particles (nZVI) synthesized using Shorea robusta (Sal) leaf extract.

In the present study, photo catalytic degradation of azo dye Congo Red was conducted using Fe nano particles (nZVI) in the presence of UV light. nZVI was biosynthesized using FeSO.7HO precursor and leaf extract of Shorea robusta (sal) as reducing agent under optimum condition of 1 mM concentration of precursor and a ratio of 1:1 Sal leaf extract to precursor. TEM and AFM images revealed formation of well dispersed spherical nano particles of 54-80 nm. SAED patterns of nZVI particles indicated its crystalline nature, while EDX result showed the presence of iron as the most abundant element. In batch experiments, optimum degradation of CR was 96% at 220 ppm CR with a dose of 1.2 g/L nZVI at pH 4 in 15 min following pseudo second order kinetics. The study suggested nZVI to be a potentially economic and ecofriendly technique for treatment of Congo Red.