Document Type: Research Paper
Department of Chemistry, Faculty of Science, Shahid Rajaee Teacher Training University, Tehran, I.R.Iran
The paper reports the preparation and photocatalytic activity of ZnO doped SnO2 nanoparticles. These nanoparticles were synthesized by hydrothermal method. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their grain sizes are about 50-100 nm. The characterization results revealed that the synthesized nanoparticles possess just crystal phases of tetragonal rutile phase of SnO2 with high quantity and good crystallinity. The photocatalytic activity of this material was investigated for congo red removal from aqueous solution under UV light irradiation. It was shown that the use of ZnO doped SnO2 nanoparticle as a photocatalyst has a better photocatalytic activity for degradation of congo red than SnO2 or TiO2 (anatase, particle size: 30 nm) alone. This good performance can be attributed to more charge separation; then the recombination of electrons and holes in ZnO doped SnO2 nanoparticle is greatly suppressed. This is the reason that the ZnO doped SnO2 nanoparticles possessed both higher photocatalytic oxidation and reduction activities than those of TiO2 or SnO2.