Preparation and Photocatalytic Properties of Ag/activated Carbon-ZnO Powders

Abstract

This research was studied the influence of type of precipitating agents (X2C2O4, X = H, Na or NH4) and amounts of activated carbon (AC) and metallic silver (Ag) on photocatalytic activity of ZnO. When Zn2+ ions reacted with C2O42, ZnC2O4.2H2O was produced as intermediate species and this compound was decomposed to ZnO after calcination at 500 °C for 1h. The ZnO prepared from H2C2O4 exhibited the highest surface area and showed the highest photocatalytic degradation of methylene blue (MB) and reactive orange (RO) under blacklight irradiation compared to the other ZnOs prepared by Na2C2O4 and (NH4)2C2O4. However, this ZnO demonstrated a low activity under visible light irradiation. Thus, the activated carbon (AC) and Ag were added into the ZnO in order to improve the photocatalytic activity of resulting composite. The experimental results showed that the Ag/AC-ZnO can degrade MB and RO under visible light irradiation without any additive while the H2O2 was the important additive for degradation of BPA. After exposure of L-929 cells to dye and BPA solution before and after photocatalysis for 72 h, the cell viability after exposure in the solution after photocatalysis was higher than in initial solution. It can conclude that the degraded products after photocatalytic reaction were less toxic than parent dye or BPA molecules.