Synthesis of highly sensitive disordered porous SnO2 aerogel composite material by the chemical deposition method: synergistic effect of a layer of CuO thin film

In this study, a new chemical deposition method was innovatively used to prepare disordered porous CuO/SnO2 aerogel composite material (CuO/SnO2-ACM). The CuO/SnO2-ACM was a p-p combined structure semiconductor, with a layer of CuO thin film formed on the surface of disordered porous SnO2 aerogel matrix material (SnO2-AMM). For the first time, the aerogel technology was used to prepare the porous tin dioxide material. The metal Cu was deposited on the surface of the SnO2-AMM to form the film. Finally, the sample was calcined, and a layer of CuO thin film was formed on the surface of the SnO2-AMM. Compared with the SnO2-AMM, the prepared CuO/SnO2-ACM showed enhanced sensitivity to NOx gas at the room temperature. When the NOx concentration was 100 ppm, the response reached 74%, and the response time was only 7.0 s. A detection limit to NOx gas of 1 ppm could be reached, with a response and response time of 15% and 26 s, respectively. In addition, excellent restorability and superior selectivity could be observed in the prepared sensor. The excellent gas sensing properties of the prepared CuO/SnO2-ACM can be attributed to the unique structure and synergistic effect of CuO thin film.