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 CdSnO3 nanocubes were sensitized with CdS quantum dots via a chemical bath deposition strategy and applied to isopropanol sensor. The novel CdS-modified CdSnO3 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/CdSnO3 composite. Combined with the catalytic action of CdS on the oxidation of isopropanol and the formation of n-n heterojunction between CdSnO3 and CdS, the sensor possessed enhanced performance in isopropanol detection. The response of the CdS/CdSnO3 sensor was 20.12 to 100 ppm isopropanol, which was about three times higher than that of pure CdSnO3. And the sensor also possessed superior selectivity to isopropanol, fast response and recovery speed (5/22s) and low optimum operating temperature (138 °C). This work has reference significance for the construction and understanding of isopropanol-sensing nanomaterials.