Enhanced photoactivity of cerium tungstate-modified graphitic carbon nitride heterojunction photocatalyst for the photodegradation of moxifloxacin

Design and optimization of visible-light-driven photocatalysts for degradation of organic pollutants is an important step towards environmental decontamination. In this study, wolframite cerium tungstate (Ce 2 (WO 4 ) 3 , (CW)) hybridized with g-C 3 N 4 (CN) nanosheets was synthesized via a simple hydrothermal route followed by an ultrasound-assisted synthesis method. The prepared Ce 2 (WO 4 ) 3 @ g-C 3 N 4 (CW@CN) heterojunction was investigated for photocatalytic degradation of the antibiotic moxifloxacin (MXF) under visible light irradiation. Structural, morphological, and optical properties as well as chemical composition of the as-synthesized heterojunction were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS) and photoluminescence (PL). MXF photocatalytic degradation by the binary nanostructure (Ce 2 (WO 4 ) 3 @ g-C 3 N 4 ) (94.1%) was the highest compared to g-C 3 N 4 (53.6%) and Ce 2 (WO 4 ) 3 (46.4%). Such enhanced activity could be ascribed to efficient suppression of the charge carriers’ recombination, leading to adequate formation of the reactive species responsible for MXF degradation. Furthermore, the Ce 2 (WO 4 ) 3 @ g-C 3 N 4 heterojunction showed remarkable stability over five consecutive cycles, with only 11.5% reduction after the 5th cycle. This work established the potential applicability of Ce 2 (WO 4 ) 3 @ g-C 3 N 4 nanostructures towards photocatalytic removal of MXF.