Facile synthesis of g-C3N4/CdWO4 with excellent photocatalytic performance for the degradation of Minocycline

Abstract

A novel g-C3N4/CdWO4 composite was formed by hydrothermal process and utilized for the removal of Minocycline (MC) antibiotic under visible light exposure. The XRD patterns of synthesized sample reveal the pure crystalline structure and phase of g-C3N4/CdWO4. The SEM images of g-C3N4/CdWO4 showed regular short rod structure with diameter in the range of 20–60 nm. These images also showed that the g-C3N4/CdWO4 structure has well contacted surfaces which enhanced the interfacial transfer of charge as a result of which the performance of photocatalyst was improved. The energy dispersive spectroscopy (EDS) images of g-C3N4, CdWO4 and g-C3N4/CdWO4 conclude that there were no impurities in the synthesized samples. SEM and EDS results confirm the interface interaction develop between g-C3N4 and CdWO4 due to hybridization. The FTIR spectrum of composite showed that the composite formed had extensively conjugated system and the band gap energies calculated for CdWO4, g-C3N4 and g-C3N4/CdWO4 were 3.31 eV, 2.67 eV and 2.71 eV respectively. A remarkable drop in photoluminescence intensity of g-C3N4/CdWO4 was observed as compared to pure g-C3N4 and CdWO4 which led to lower recombination rate of photo-induced charge carriers and hence a higher photocatalytic performance for the degradation of minocycline under visible-light irradiation. Keywords: Photocatalyst, Recombination rate, Charge carries, Photocatalytic performance, Minocycline