To detect low concentrations of formaldehyde selectively, the sensing properties of SnO2 nanostructured are enhanced by modifying with p-type semiconductor NiO. In this study, a nanostructured SnO2/NiO composite was prepared by a simple hydrothermal method. The X-ray photoelectron spectroscopy (XPS) peak in 532.4 eV proved that the existence of the SnO2/NiO composite structure increased the amount of adsorbed oxygen O− and O2− significantly. Gas-sensing tests showed that these mixed phases SnO2/NiO are highly promising for gas sensor applications, as the gas response for formaldehyde was significantly enhanced in gas response, selectivity at an operating temperature of 230 °C. The sensor fabricated by SnO2/NiO composite can detect as low as 1 ppm of formaldehyde at 230 °C, and the corresponding response is 1.57. The results of physicochemical properties tests of the samples show that the enhancement in sensitivity and selectivity is attributed to the oxygen vacancies and heterojunction between SnO2 and NiO. The SnO2/NiO composites can be applied to sensitive materials of formaldehyde sensors.

为了选择性地检测低浓度的甲醛，通过用p型半导体NiO改性可以增强纳米结构SnO 2的传感性能。在这项研究中，通过简单的水热法制备了纳米结构的SnO 2 / NiO复合材料。在532.4 eV的X射线光电子能谱（XPS）峰证明SnO的存在2 /氧化镍复合结构增加的吸附氧O量-和O 2-显著。气敏测试表明这些混合相SnO 2/ NiO在气体传感器应用中非常有前途，因为在230°C的工作温度下，甲醛的气体响应在气体响应，选择性方面得到了显着提高。由SnO 2 / NiO复合材料制成的传感器在230°C时可以检测到低至1 ppm的甲醛，相应的响应为1.57。样品的理化性质测试结果表明，灵敏度和选择性的提高归因于SnO 2和NiO之间的氧空位和异质结。SnO 2 / NiO复合材料可应用于甲醛传感器的敏感材料。