Division of Materials Science and Engineering, Hanyang University , Seoul 04763, Republic of Korea.
The Research Institute of Industrial Science, Hanyang University , Seoul 04763, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Sep 20;9(37):31667-31682. doi: 10.1021/acsami.7b02533. Epub 2017 Sep 11.
We obtained extremely high and selective sensitivity to NO gas by fabricating graphene-SnO nanocomposites using a commercial microwave oven. Structural characterization revealed that the products corresponded to agglomerated structures of graphene and SnO particles, with small secondary SnO (x ≤ 2) nanoparticles deposited on the surfaces. The overall oxygen atomic ratio was decreased with the appearance of an SnO (x < 2) phase. By the microwave treatment of graphene-SnO nanocomposites, with the graphene promoting efficient transport of the microwave energy, evaporation and redeposition of SnO nanoparticles were facilitated. The graphene-SnO nanocomposites exhibited a high sensor response of 24.7 for 1 ppm of NO gas, at an optimized temperature of 150 °C. The graphene-SnO nanocomposites were selectively sensitive to NO gas, in comparison with SO, NH, and ethanol gases. We suggest that the generation of SnO nanoparticles and the SnO phase in the matrix results in the formation of SnO/SnO homojunctions, SnO/SnO (x < 2) heterojunctions, and SnO/graphene heterojunctions, which are responsible for the excellent sensitivity of the graphene-SnO nanocomposites to NO gas. In addition, the generation of surface Sn interstitial defects is also partly responsible for the excellent NO sensing performance observed in this study.
我们使用商用微波炉制造了石墨烯-SnO 纳米复合材料，从而获得了对 NO 气体极高且具有选择性的灵敏度。结构特征表明，产物对应于石墨烯和 SnO 颗粒的团聚结构，少量的二次 SnO（x ≤ 2）纳米颗粒沉积在表面上。随着 SnO（x < 2）相的出现，总氧原子比降低。通过微波处理石墨烯-SnO 纳米复合材料，由于石墨烯促进了微波能量的有效传输，因此促进了 SnO 纳米颗粒的蒸发和再沉积。在优化温度为 150°C 时，石墨烯-SnO 纳米复合材料对 1ppm 的 NO 气体表现出 24.7 的高传感器响应。与 SO、NH 和乙醇气体相比，石墨烯-SnO 纳米复合材料对 NO 气体具有选择性灵敏度。我们认为，SnO 纳米颗粒的生成和基体中的 SnO 相形成了 SnO/SnO 同质结、SnO/SnO（x < 2）异质结和 SnO/石墨烯异质结，这是石墨烯-SnO 纳米复合材料对 NO 气体具有优异灵敏度的原因。此外，表面 Sn 间隙缺陷的产生也部分解释了本研究中观察到的优异的 NO 传感性能。
