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半导体复合材料中的光生载流子动力学过程是影响其光催化性能的重要因素之一。该工作以二水合氯化亚锡(SnCl_2·2H_2O)为原料,NaOH为沉淀剂,采用一步溶剂热法制备了锡的氧化物纳米SnO-SnO_2复合材料,并利用SEM、XRD、TEM和Uv-Vis光谱等对产物进行了表征。结果表明通过控制反应条件可以获得粒径约为10～20 nm SnO-SnO_2复合材料和粒径约为10 nm的四方相SnO_2颗粒,分散性较好。光催化性能研究表明,纳米SnO-SnO_2复合材料完全催化降解罗丹明B(Rh B)的时间比单纯纳米SnO_2颗粒减少50%。针对这一结果,利用瞬态表面光电压(TSPV)技术分别对上述纳米材料的光生载流子动力学过程进行了讨论,结果表明,纳米SnO-SnO_2复合结构的构建可以有效地促进光生载流子的分离、抑制SnO_2表面光生载流子的复合、提高材料表面的光生载流子的寿命,进而显著增强光催化性能。
The photo-generated carrier dynamics in semiconductor composites is one of the important factors affecting the photocatalytic performance. In this work, tin oxide SnO2-SnO 2 composite was prepared by one-step solvothermal method using SnCl 2 · 2H 2 O as raw material and NaOH as precipitator. SEM, XRD, TEM and Uv- Vis spectra and other products were characterized. The results show that the SnO 2 particles with a size of about 10-20 nm and the tetragonal SnO 2 particles with a size of about 10 nm can be obtained by controlling the reaction conditions. The results of photocatalytic activity show that the time for complete catalytic degradation of rhodamine B (Rh B) by nano-SnO-SnO 2 composites is 50% less than that of pure nano-SnO 2 particles. According to this result, the photogenerated carrier dynamics of the nanomaterials are discussed by using the transient surface photovoltage (TSPV) technique respectively. The results show that the nanocrystalline SnO-SnO 2 composite structure can effectively promote the photocarrier , Which can restrain the recombination of photocarriers on the surface of SnO 2 and increase the lifetime of photocarriers on the surface of the material, thereby significantly enhancing the photocatalytic performance.