Abstract
A sol-gel method was used to prepare a cerium dioxide nanoparticles, and an impregnationmethod was used to prepare cerium dioxide-chitosan or silver doped cerium dioxide or silver doped cerium dioxide-chitosan. Different techniques, such as UV-Vis, XPS, TEM, XRD, PL and BET surface area, were used to characterize the prepared materials. The results reveal that agglomeration of cerium dioxide was decreased by addition of chitosan. The doping of silver and chitosan to cerium dioxide nanoparticles play an important role in the control electron-hole recombination rate. The photocatalytic performance of cerium dioxide, Ag-cerium dioxide, cerium dioxide-chitosan and Ag-cerium dioxide-chitosan nanoparticles was studied by measuring its photocatalytic oxidation of malachite green dye under visible light. Photocatalytic parameters such as the type of doped materials, photocatalyst dose and photocatalytic stability were also studied. The photocatalytic activity of cerium dioxide is smaller than that of cerium dioxide-chitosan and silver doped cerium dioxide-chitosan nanoparticles. This can be attributed to the fact that the addition of silver or chitosan or silver-chitosan to cerium dioxide nanoparticles decreases the electron-hole recombination rate or alternatively due to the transfer of electrons between silver and cerium dioxide nanoparticles.