Facile synthesis of Ag/Ag3PO4/AMB composite with improved photocatalytic performance

Ag3PO4 exhibits extremely high photo-oxidative capabilities for organic pollutants decomposition under solar light. However, the relatively large crystallite size of Ag3PO4 lowers its light response, while the high conduction band potential intensifies the reduction to Ag by the light induced electron, limiting the practical application of Ag3PO4. To overcome these drawbacks, we herein adopted a facile liquid phase deposition method to load Ag3PO4 onto amino-modified biochar which is an abundant and cheap byproduct of biomass pyrolysis to prepare renewable energy. The as-prepared composite (Ag/Ag3PO4/AMB) exhibited greatly enhanced photocatalytic performance to amoxicillin degradation compared with pure Ag3PO4. The results show that almost 80% amoxicillin was decomposed in 120 min in the presence of Ag/Ag3PO4/AMB, whereas only 65% of the amoxicillin was degraded with pure Ag3PO4. Multiple characterizations including X-ray diffraction (XRD), scanning electron microscope (SEM), MR, Raman, and XPS revealed that Ag3PO4 particles were evenly distributed on the surface of biochar, and a few Ag NPs were also generated due to the reduction effect of AMB. IJV-vis diffuse reflectance spectra (DRS) analysis revealed that the composite had good visible light response, while electrochemical impedance spectroscopy (EIS) measurements indicated AMB improved the efficiency of charge separation and electron transfer. In addition, EPR determination suggested that the oxidant formed in photocatalysis systems under visible light irradiation plays an important role in the degradation of amoxicillin. (C) 2016 Elsevier B.V. All rights reserved.