CuO-TiO2/graphene ternary nanocomposite for highly efficient visible-light-driven photocatalytic degradation of bisphenol A

Abstract

To prepare a visible light-responsive photocatalyst of coupled CuO-TiO2 anchored on graphene oxide (CuO-TiO2/GO) nanocomposite, CuO-TiO2 photocatalyst was initially synthesized by surfactant assisted-sol-gel method and then anchored on GO via a simple hydrothermal process. The results of XPS, TEM, SEM and Raman analyses indicated that the being of CuO-TiO2 particles are decorated on the surface of GO effectively, accordingly resulting in the effective photo-generated charge separation, which was evaluated and supported via PL spectra and time-resolved PL spectra. The photocatalytic performance of CuO-TiO2/GO could also be improved via adjusting the proportion between CuO-TiO2 and GO. The best GO percentage is 10wt%, at which CuO-TiO2/GO composite exhibited the excellent BPA removal percentage of 56.5% compared with CuO-TiO2 photocatalyst (28.8%) after 300 min. of visible light. In addition, the postulated mechanism of the photocatalytic performance of this CuO-TiO2/GO ternary nanocomposite has been evaluated. The dominant reactive oxygen species (ROS) formed during the photocatalytic reactions were determined to be O2.− and .OH. The effect of the presence of anions on BPA degradation was also discussed in dept. While Cl− and NO3− have an inhibitory effect, HCO3− and CO32− have an accelerating and great improving effect towards photocatalytic degradation of BPA. This work indicates that this CuO-TiO2/GO hybrid ternary nanocomposite can also be performed as a highly potential photocatalyst in secondary treatments to degrade other organic pollutants.