Enhanced photocatalytic degradation of rhodamine B over Ag3PO4/Polyaniline/NiFe2O4 nanocomposite under solar light irradiation

Abstract

In this study, a nanocomposite of Ag3PO4/Polyaniline(PANI)/NiFe2O4 was synthesized and studied on degradation of rhodamine B (RhB) in water under solar light irradiation. The nanocomposite was characterized using powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Ultraviolet-visible (UV-vis) differential reflectance spectroscopy (DRS). The best photocatalytic nanocomposite (Ag3PO4/3%PANI/10%NiFe2O4) showed six-fold higher degradation rate constant than of pristine Ag3PO4. Moreover, introduction of PANI/NiFe2O4 into Ag3PO4 significantly enhance the recyclability of the nanocomposite (stable after 3 cycles) whereas pristine Ag3PO4 degraded even after first cycle. Radical scavenger studies with t-butyl alcohol, disodium ethylenediaminetetraacetic acid, and ascorbic acid indicated that both holes and electron participate in the degradation of RhB. We hypothesized that the presence of PANI and NiFe2O4 in the nanocomposite enhanced its hole and electron transport, respectively, facilitating efficient electron-hole separation. Therefore, large number of holes accumulates in valance band of Ag3PO4 that enhanced the degradation of RhB dye in water under solar light irradiation.