rGO-SnO2纳米复合物制备及室温下NH3气敏性能

采用沉淀-焙烧法制备了室温下对NH3具有高灵敏度和高选择性的rGO-SnO2纳米复合材料。利用X射线衍射（XRD），傅里叶红外光谱（FTIR），X射线光电子能谱（XPS），扫描电子显微镜（SEM），透射电子显微镜（TEM）和比表面积（BET）表征分析了纯SnO2与rGO(1.0%)-SnO2纳米复合物的属性。与纯SnO2相比，rGO(1.0%)-SnO2纳米复合物中SnO2晶体尺寸较小，约为6~20nm，比表面积更大，为33m2/g；rGO(1.0%)-SnO2纳米复合材料对0.01% NH3的灵敏度达到了49.6%，是相同NH3浓度下纯SnO2灵敏度的2.1倍，并且响应和恢复时间分别为21s和204s，比纯SnO2缩短了24s和10s，具有良好的重复性，选择性与稳定性；rGO(1.0%)-SnO2纳米复合材料优良的气敏性能是由rGO与SnO2产生的p-n异质结以及溶解的NH3电离出导电离子共同作用的结果。

Preparation of rGO-SnO2 Nanocomposite and its Gas Sensing Property of NH3 at Room Temperature

The high sensitivity and selectivity of rGO-SnO2 nanocomposites for NH3 at room temperature were prepared by precipitation-roasting method. X-ray diffraction (XRD), Fourier infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area (BET) were used to characterize and analyze pure SnO2 with rGO (1.0%)-SnO2 nanocomposites. Compared with the pure SnO2, the crystal size of SnO2 in the rGO (1.0%)-SnO2 nanocomposites is smaller, about 6 ~ 20 nm, with a larger specific surface area of 33m2/g. The sensitivity of rGO (1.0%)-SnO2 nanocomposites to 0.01% NH3 reached 49.6%, which was 2.1 times of that of pure SnO2 at the same NH3 concentration, and the response and recovery time were 21 s and 204 s, respectively, which was 24 s and 10 s shorter than that of pure SnO2, with good repeatability, selectivity and stability. The excellent gas sensing properties of rGO (1.0%)-SnO2 nanocomposites can be attributed to the interaction of p-n heterojunction produced by rGO and SnO2 and dissolved NH3 ionized conductive ions.