School of Material Science and Engineering , University of Jinan , 250022 Jinan , P. R. China.
ACS Appl Mater Interfaces. 2019 Feb 27;11(8):8601-8611. doi: 10.1021/acsami.8b22357. Epub 2019 Feb 13.
Morphology-tunable C-N/SnO-based hierarchical microspheres with good gas sensitivity for triethylamine (TEA) have been fabricated via facile electrospinning and a subsequent calcination process. The reaction temperature and modifying calcining technology played a dominant role for the morphological evolution from precursor fibers to microspherical shapes and the formation of C-N-decorated SnO phase composition. C-N/SnO/ZnO composites with tunable crystallinity, microstructure, and gas-sensing performance were strictly dependent on the added amount of Zn element. Fascinatingly, the constructed C-N/SnO/ZnO/Au composites can not only precisely regulate the crystal size, dispersion status, loading position, and content of Au nanoparticles but also display excellent gas-sensing properties with ultrasensitivity and high selectivity under various temperature detections. The response of C-N/SnO/ZnO/Au composites can reach up to approximately 1970, calculated to be 121.6 and 23.6 times for 50 ppm TEA molecules at optimal conditions compared with C-N/SnO and C-N/SnO/ZnO microspheres, respectively, actually representing the highest response value at high temperatures reported to date. The superior long-aging stability of sensing behaviors and phase structures can be also observed after 1 month. More importantly, novel C-N/SnO/ZnO/Au sensors were employed for availably detecting low-concentration volatiles released from the storage procedure of fishes at 80 °C, indicating the practical application in chemical detectors and biosensors at low temperature. The novel gas-sensing mechanisms derived primarily from the combination of phase compositions, morphologies, and unique surface/interface transfer processes of C-N/SnO/ZnO/Au composites are presented and investigated in detail, which will contribute to the design and development of other semiconductor-based composite sensors.
通过简便的静电纺丝和随后的煅烧工艺，制备了具有良好气体敏感性的形态可调 C-N/SnO 基分级微球，用于三乙胺（TEA）。反应温度和修饰煅烧技术对前驱体纤维到微球形的形态演变以及 C-N 修饰 SnO 相组成的形成起着主导作用。具有可调结晶度、微观结构和气体传感性能的 C-N/SnO/ZnO 复合材料严格依赖于添加的 Zn 元素的量。有趣的是，构建的 C-N/SnO/ZnO/Au 复合材料不仅可以精确调节 Au 纳米粒子的晶体尺寸、分散状态、负载位置和含量，而且在各种温度检测下表现出优异的气体传感性能，具有超高灵敏度和高选择性。在最佳条件下，C-N/SnO/ZnO/Au 复合材料的响应可达约 1970，与 C-N/SnO 和 C-N/SnO/ZnO 微球相比，50 ppm TEA 分子的响应分别高达 121.6 和 23.6 倍，实际上代表了迄今为止高温下的最高响应值。在 1 个月后，也可以观察到传感行为和相结构的优异长期稳定性。更重要的是，新型 C-N/SnO/ZnO/Au 传感器可用于有效检测鱼类储存过程中释放的低浓度挥发性物质，表明其在低温下化学探测器和生物传感器中的实际应用。新型气敏机制主要源自 C-N/SnO/ZnO/Au 复合材料的相组成、形态和独特的表面/界面传输过程的结合，并进行了详细研究，这将有助于其他基于半导体的复合传感器的设计和开发。
