g-C3N4/SnO2异质分层结构的水热合成及其气敏性能研究

Hydrothermal synthesis of hierarchical g-C3N4/SnO2 heterostructures and their enhanced gas sensing properties

采用一步水热法合成了不同比例(0,1%,3%,5%,7%,9%(质量分数))异质分层结构的g-C3N4/SnO2复合材料。利用X射线衍射(XRD)、红外光谱(FT-IR)、拉曼光谱(Raman)、X射线光电子能谱(XPS)、扫描(SEM)和透射(TEM)电子显微镜、BET比表面积测试和发致发光光谱(PL)对材料的晶体结构、形貌、化学组成和光学性能进行了表征。将制备的复合材料应用于气体传感器,对乙醇进行气敏性能测试。结果表明,复合5%(质量分数) g-C3N4的SnO2气体传感器的最佳工作温度为270℃,对40×10^-6乙醇的灵敏度达到77.5,是纯SnO2气体传感器的灵敏度的8.4倍。最后,对复合材料g-C3N4/SnO2的气敏性能优化机理进行了分析讨论。

Different proportions(0, 1%, 3%, 5%, 7%, 9 wt%) of hierarchical g-C3N4/SnO2 heterostructures were synthesized by one-step hydrothermal method. The crystal structure, morphology and optical properties of the materials were investigated by X-ray diffraction(XRD), infrared spectroscopy(FT-IR), Raman spectroscopy(Raman), X-ray photoelectron spectroscopy(XPS), electron microscopy(SEM and TEM), BET specific surface area measurement and photoluminescence spectroscopy(PL). Meanwhile, the gas sensing performances of g-C3N4/SnO2 nanostructures were investigated towards ethanol. The results showed that the gas response of 5 wt% g-C3N4/SnO2 based sensor was 77.5×10^-6 to 40×10^-6 ethanol at the optimum working temperature of 270 ℃, which was about 8.4 times higher than that of the pure SnO2. Finally, the enhanced gas sensing mechanism of the g-C3N4/SnO2 nanocomposite was discussed.