A room-temperature aniline sensor based on Ce doped ZnO porous nanosheets with abundant oxygen vacancies

How to improve the selectivity and sensitivity of semiconductor metal oxide (SMO) based gas sensors at room temperature is still a big challenge. In this paper, different content of Ce doped ZnO porous nanosheets were successfully synthesized via a facile and controllable hydrothermal method and their sensing properties were investigated. 1 at% Ce doped ZnO (CZO-1) sensor exhibited a high response (S = 15.1 for 100 ppm aniline), and excellent selectivity toward aniline against other gases at room temperature compared with pristine ZnO. The abundant oxygen vacancies (OV), high specific surface area and the interface interaction between of CeO2 and ZnO effectively enlarged the resistance variation due to the change in oxygen adsorption. The two-dimensional (2D) porous structure also plays an important role in the excellent sensing performance due to the excellent electron transport capability and abundant gas diffusion channels. DFT study results indicated the interaction between ZnO and aniline could be enhanced by introducing OV and Ce doping. Thus, this work indicated that the CZO composites could be a potential candidate for aniline detection at room temperature.