Din Salah Ud, Haq Mahmood Ul, Sajid Muhammad, Khatoon Rabia, Chen Xuehua, Li Li, Zhang Manjun, Zhu Liping
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027, People's Republic of China.
Nanotechnology. 2020 Sep 25;31(39):395502. doi: 10.1088/1361-6528/ab98bb. Epub 2020 Jun 2.
In this work, we report the spontaneous formation of NiO nanoparticles-decorated onto smooth SnO nanofibers, which is an inexpensive and scalable method for yielding a high composite surface area via a simple two-step synthesis process based on electrospinning and the hydrothermal method. A Nickel Oxide proton-conducting electrolyte is deposited homogeneously over a large surface area in a transparent solution, mixed and decorated onto Tin dioxide nanofibers, as evidenced by cross sectional imaging of the electrospun nanofibers. The composite based on nanoparticle-decorated fibers enlarges the surface area of the exposed electrolyte, which fundamentally improves the overall gas sensing performance. The crystal structure, morphology, and physio-chemical surface state of the NiO/SnO-based specimen are comprehensively examined using XRD, SEM, TEM, HRTEM, EDX, and photoelectron (XPS) spectroscopy. The composite based on NiO/SnO nanoparticle-decorated fibers exhibits an optimistic mesoporous nature with a huge specific area, which is key for superior gas sensors. The result reveals that NiO/SnO nanoparticle-decorated fibers with an average size of 180-260 nm in diameter, where the average length of fibers was about 1.5 μm. The composite-based heterojunction of NiO/SnO nanoparticle-decorated fibers enhances the adsorption of oxygen molecules, which show fast response, good selectivity and quick recovery speed against ethanol gas at an optimal temperature of about 160 °C. The maximum sensitivity response of the sensor-based composite NiO/SnO nanoparticle-decorated fibers was 23.87 in respect of 100 ppm ethanol gas at a low temperature of 160 °C; this is approximately about 7.2 times superior to that of pure SnO nanofibers. The superior gas sensing capabilities of a composite based on NiO/SnO nanoparticle-decorated fibers may be attributable to the enhanced catalytic effect of the small sized NiO nanoparticles on smooth SnO nanofibers, together with the p/n heterojunction effects between NiO and SnO heterostructures.
在本工作中，我们报道了在光滑的SnO纳米纤维上自发形成的NiO纳米颗粒，这是一种通过基于静电纺丝和水热法的简单两步合成工艺来获得高复合表面积的廉价且可扩展的方法。氧化镍质子传导电解质均匀地沉积在透明溶液中的大表面积上，混合并装饰在二氧化钛纳米纤维上，这一点通过静电纺纳米纤维的横截面成像得到了证实。基于纳米颗粒装饰纤维的复合材料扩大了暴露电解质的表面积，从根本上提高了整体气敏性能。使用XRD、SEM、TEM、HRTEM、EDX和光电子（XPS）光谱对基于NiO/SnO的样品的晶体结构、形态和物理化学表面状态进行了全面研究。基于NiO/SnO纳米颗粒装饰纤维的复合材料表现出具有巨大比表面积的理想介孔性质，这是优异气敏传感器的关键。结果表明，NiO/SnO纳米颗粒装饰纤维的平均直径为180 - 260 nm，纤维的平均长度约为1.5μm。基于NiO/SnO纳米颗粒装饰纤维的复合材料异质结增强了氧分子的吸附，在约160°C的最佳温度下，对乙醇气体表现出快速响应、良好的选择性和快速恢复速度。基于复合NiO/SnO纳米颗粒装饰纤维的传感器在160°C低温下对100 ppm乙醇气体的最大灵敏度响应为23.87；这大约是纯SnO纳米纤维的7.2倍。基于NiO/SnO纳米颗粒装饰纤维的复合材料优异的气敏性能可能归因于光滑SnO纳米纤维上小尺寸NiO纳米颗粒增强的催化作用，以及NiO和SnO异质结构之间的p/n异质结效应。
