School of Materials Science and Engineering, University of Shanghai for Science & Technology, No. 516 JunGong Road, Shanghai 200093, China.
Molecules. 2019 Dec 20;25(1):35. doi: 10.3390/molecules25010035.
In this work, we reported a formaldehyde (HCHO) gas sensor with highly sensitive and selective gas-sensing performance at low operating temperature based on graphene oxide (GO)@SnO nanofiber/nanosheets (NF/NSs) nanocomposites. Hierarchical SnO NF/NSs coated with GO nanosheets showed enhanced sensing performance for HCHO gas, especially at low operating temperature. A series of characterization methods, including X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) were used to characterize their microstructures, morphologies, compositions, surface areas and so on. The sensing performance of GO@SnO NF/NSs nanocomposites was optimized by adjusting the loading amount of GO ranging from 0.25% to 1.25%. The results showed the optimum loading amount of 1% GO in GO@SnO NF/NSs nanocomposites not only exhibited the highest sensitivity value (R/R = 280 to 100 ppm HCHO gas) but also lowered the optimum operation temperature from 120 °C to 60 °C. The response value was about 4.5 times higher than that of pure hierarchical SnO NF/NSs (R/R = 64 to 100 ppm). GO@SnO NF/NSs nanocomposites showed lower detection limit down to 0.25 ppm HCHO and excellent selectivity against interfering gases (ethanol (CHOH), acetone (CHCOCH), methanol (CHOH), ammonia (NH), methylbenzene (CH), benzene (CH) and water (HO)). The enhanced sensing performance for HCHO was mainly ascribed to the high specific surface area, suitable electron transfer channels and the synergistic effect of the SnO NF/NSs and GO nanosheets network.
在这项工作中，我们报道了一种基于氧化石墨烯（GO）@SnO 纳米纤维/纳米片（NF/NSs）纳米复合材料的甲醛（HCHO）气体传感器，该传感器在低温下具有高灵敏度和选择性的气体传感性能。用 GO 纳米片包覆的分层 SnO NF/NSs 表现出对 HCHO 气体的增强传感性能，特别是在低温下。采用 X 射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、透射电子显微镜（TEM）、X 射线光电子能谱（XPS）和 Brunauer-Emmett-Teller（BET）等一系列表征方法对其微结构、形貌、组成、表面积等进行了表征。通过调整 GO 的负载量（从 0.25%到 1.25%），优化了 GO@SnO NF/NSs 纳米复合材料的传感性能。结果表明，在 GO@SnO NF/NSs 纳米复合材料中，最佳的 GO 负载量为 1%，不仅表现出最高的灵敏度值（R/R = 280 至 100 ppm HCHO 气体），而且将最佳工作温度从 120°C 降低到 60°C。响应值比纯分层 SnO NF/NSs（R/R = 64 至 100 ppm）高约 4.5 倍。GO@SnO NF/NSs 纳米复合材料对 HCHO 的检测下限低至 0.25 ppm，对干扰气体（乙醇（CHOH）、丙酮（CHCOCH）、甲醇（CHOH）、氨（NH）、甲基苯（CH）、苯（CH）和水（HO））具有优异的选择性。对 HCHO 具有增强的传感性能主要归因于高比表面积、合适的电子传输通道以及 SnO NF/NSs 和 GO 纳米片网络的协同效应。
