Improvement of isopropanol sensing performance by surface sensitization of CdSnO3 nanocubes with CdS quantum dots

Perovskite oxides are promising gas-sensing materials due to the stable chemical properties and suitable energy band structure. Quantum dots are low-dimensional nanomaterials with large specific surface areas and rich active sites, which are beneficial to sensing process. Here, the surface of porous CdSnO 3 nanocubes were sensitized with CdS quantum dots via a chemical bath deposition strategy and applied to isopropanol sensor. The novel CdS-modified CdSnO 3 porous cubes had a large specific surface area. In addition, DFT calculations show that the adsorption of isopropanol by CdS contributes to the recognition of isopropanol among alcohols by CdS/CdSnO 3 composite. Combined with the catalytic action of CdS on the oxidation of isopropanol and the formation of n-n heterojunction between CdSnO 3 and CdS, the sensor possessed enhanced performance in isopropanol detection. The response of the CdS/CdSnO 3 sensor was 20.12 to 100 ppm isopropanol, which was about three times higher than that of pure CdSnO 3 . And the sensor also possessed superior selectivity to isopropanol, fast response and recovery speed (5/22 s) and low optimum operating temperature (138 °C). This work has reference significance for the construction and understanding of isopropanol-sensing nanomaterials.