Synthesis of Quasi―monodispersed SnO2 Microspheres via Microwave Solvothermal Method

Quasi―monodispersed SnO2 microspheres were successfully prepared by microwave solvothermal method at 180 or 30 min, using PEG―6000 (0.12 mmol) as template, SnCl4·5H2O and urea as raw materials. The as―prepared samples were characterized by XRD, SEM, TEM, and FT―IR. Futhermore, the photoluminescence (PL) property of the products were investigated by PL spectroscope. The results show that the SnO2 microspheres with diameter about 1.3 um are self―assembled by nanocrystals. The surface of microspheres is smooth and their morphology is well preserved after calcined at 400 or 2 h. The peak at 550 cm―1 in FT―IR spectra may belong to the surface vibration mode, which due to the surface structure changes of the samples. A strong and broad band (320―450 nm) is exhibited in the PL spectra for uncalcined product. However, the intensity of emitting band is greatly decreased after calcination, which proves that the lattice defects of the products are of great importance to the near band edge emission.