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

Abstract

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 NO_x gas at the room temperature. When the NO_x concentration was 100 ppm, the response reached 74%, and the response time was only 7.0 s. A detection limit to NO_x 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.