Preparation of Ag‐doped TiO2nanoparticles for photocatalytic degradation of acetamiprid in water

Abstract

AbstractBACKGROUND:Surface modification by doping with metal ions and organic polymers has been proven to be an efficient route to improve the photocatalytic activity of TiO2. Pesticide photocatalysis has been conducted with fine TiO2particles suspended in an aqueous phase.RESULTS:It has been found that the Ag dopant accelerates TiO2anatase to rutile transformation. At relatively low Ag concentrations (2–6%), anatase grain sizes decreased and specific surface areas of the TiO2powders increased. The presence of Ag in crystalline TiO2was found to increase the photocatalytic activity of TiO2in the photocatalytic degradation of acetamiprid at 25 °C.CONCLUSION:All photocatalytic degradations of acetamiprid followed pseudo‐first‐order degradation kinetics (Ct=C0e−kt) and parameters like the concentration of doped Ag appeared to play an important role affecting the reaction rate. The photocatalytic degradation velocity constant (k) was found to increase quickly with the Ag content, increasing fromn= 0.02 to 0.06, and decreased slowly fromn= 0.08 to 0.12. The half‐lives of degradation (t1/2) were 18.8, 11.3, 16.2, 10.0, 6.9, 8.4 and 14.7 min atn= 0, 0.02, 0.04, 0.06, 0.08 and 0.12, respectively. The optimal mole percentage of Ag in TiO2should be between 4% and 8%. Copyright © 2008 Society of Chemical Industry