Photocatalytic Degradation of Naphthol Green B Dye Using Coupled CdS-ZnMoO₄ in UV-A Light Irradiation.

Abstract

At present, nanotechnology field development makes a major role in photocatalysis. CdS-ZnMoO₄ (36.6 wt%) coupled nanophotocatalyst is synthesized using facile hydrothermal method. The CdSZnMoO₄ catalyst shows superior photocatalytic activity in the Naphthol Green B (NGB) dye degradation in UV-A (365 nm) light irradiation. XRD analysis reveals the monoclinic structure of ZnMoO₄, cubic structure of CdS. PL shows lesser the recombination (e--h+) rate of electron-hole pair formation. UV-Vis-DRS reveals an increase in absorption in entire visible region while loading with CdS. SEM images indicate that CdS-ZnMoO₄ has nanofibrous structure. EDS reveal that Cd and S are present on the ZnMoO₄ surface. ECM indicates the division of homogeneity in elements. SAED pattern of HR-TEM images proved high crystalline properties of the catalyst. XPS reveals the different oxidation states and term-symbols of Cd, S, Zn, Mo and O in this catalyst with corresponding binding energies. CdS-ZnMoO₄ (18.5 m²g-1) has a higher surface area compared to ZnMoO₄ (10.8 m²g-1). Current densities obtained from CV reveals the higher cyclic movement of electrons (electrochemical activity) of CdS-ZnMoO₄. An effective parameters for photodegradability of NGB dye by CdS-ZnMoO₄ was analyzed.