准单分散SnO2微球的微波溶剂热合成

以聚乙二醇(PEG, Mn=6000)为模板剂, 结晶四氯化锡(SnCl₄·5H₂O)和尿素为原料, 采用微波溶剂热法在180℃、添加0.12 mmol PEG的条件下制备出了单分散性良好的SnO₂微球. 通过XRD、SEM、TEM和FT-IR等分析手段对产物进行表征, 并结合光致发光(PL)谱研究了产物的发光性能. 结果表明: SnO₂微球是由大量细小晶粒堆积而成的, 微球直径约1.3 um. 经400℃煅烧2 h后, 微球表面致密光滑且直径未发生明显变化. FT-IR谱图中550 cm^-1处吸收峰应为表面结构改变引起的表面振动模式. PL谱表明煅烧前SnO₂微球在320~450 nm处具有宽而强的发射带, 煅烧后发射带强度大幅下降, 说明产物的晶格缺陷对近带边发射有重要影响.

Synthesis of Quasi-monodispersed SnO2 Microspheres via Microwave Solvothermal Method

Quasi-monodispersed SnO₂ microspheres were successfully prepared by microwave solvothermal method at 180℃ for 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℃ for 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.