UV light driven photocatalytic degradation of ibuprofen drug by polyaniline supported rGO@MnO2 nanocomposite

Abstract

The present study exfoliates the successful synthesis of PANI–rGO@MnO2 NC using reinforcement of Manganese (IV) oxide nanoparticles (MnO2 NPs) in the reduced graphene oxide (rGO) matrix and then in situ copolymerization of aniline monomer. The synthesized material was characterized by different analytical techniques such as FTIR, XRD, SEM-EDX, DLS, TEM, XPS, and UV–Vis spectroscopic methods which confirmed the successful synthesis of the material. Cyclic voltammetry (CV) analysis indicated an improved current density for the synthesized PANI–rGO@MnO2 NC which suggest that attachment of MnO2 with PANI and rGO resulted in improved electron transfer process and slow rate of electro-hole recombination. The UV–Vis spectroscopy also supports the results exhibited by CV and suggested that the combination of rGO, MnO2 with PANI resulted in a material with enhanced optical properties with an energy bandgap of 1.45 eV. The synthesized material was investigated for the photocatalytic degradation of ibuprofen (IBP) drug and exhibited 93% photocatalytic efficiency towards IBP degradation at pH 4, 10 mg of catalyst dose, 25 mg L−1 IBP concentration, and 120 min of UV irradiation. The photocatalytic data was best simulated by Langmuir-Hinshelwood (L–H) pseudo-first-order models to explain the kinetics of degradation and the value of the apparent rate constant (kapp) was found to be 0.027 min−1 for 10 mg L−1 IBP, 0.032 min−1 for 15 mg L−1 IBP, 0.039 min−1 for 20 mg L−1 IBP and 0.047 min−1 for 25 mg L−1 IBP. The scavenger experiments revealed the primary role of superoxide (O2−) radicals in the degradation of IBP and observed a total organic carbon (TOC) reduction of 72% in 120 min of UV irradiation.