Use of g-C3 N4 /ZnO/CdS as A Photocatalyst for Degradation of Brilliant Green

The photocatalytic degradation of brilliant green was observed under visible light irradiation using ternary composite g-C3 N4 /ZnO/CdS. Ternary composite was synthesized by preparing binary composite of gC3 N4 /ZnO in deionized (DI) water and followed by addition of CdS. The ternary composite was characterized by various techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray analysis (EDX). The rate of degradation of brilliant green was observed by measuring absorbance at 625 nm. Effect of pH, concentration of dye, amount of catalyst and light intensity was observed on the rate of degradation. The degradation efficiency was found to be 91.7% in 2 h at pH = 8.0, amount of catalyst = 0.06 g, dye concentration = 0.8 x 10-5 M, and light intensity = 70.0 mW cm-2. The rate constant for typical run was observed as 3.55 x 10-4 s-1. The scavenger study indicated that the hydroxy radical (•OH) and hole (h+) are the active oxidizing species in this process.