Visible light responsive Cu-N/TiO<inf>2</inf> nanoparticles for the photocatalytic degradation of bisphenol A

Visible light active co-doped Cu-N/TiO2 photocatalyst was synthesized by the sol-gel method. The synthesized catalysts were characterized by X-ray diffraction (XRD), field-emission transmission electron microscope (FE-TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and UV–visible diffuse reflectance spectrophotometry (UV-vis DRS). The co-doping with Cu-N reduced the bandgap (∼2.83 eV) and extended the optical absorption range of TiO2 catalysts to the visible region. The incorporation of Cu and N on TiO2 lattice results in sub-conduction and valence band formation, which enhanced the photoactivity and electron-hole generation rate. The visible light activity of Cu-N/TiO2 was evaluated via photocatalytic degradation of bisphenol A (BPA) under blue LED illumination. The maximum BPA degradation of 42.7% was observed at 0.5 g L–1 catalyst dosage, initial pH of BPA solution ¼ 8.2, and initial BPA concentration of 10 ppm. Further, a possible mechanism of photocatalytic degradation of BPA was also established.