Isopropanol gas sensor based on CoSnO3/SnO2/Zn2SnO4 ternary heterostructure with high response

In this study, we successfully constructed a CoSnO₃/SnO₂/Zn₂SnO₄ ternary heterojunction composite, and developed a high-performance isopropanol gas sensor. Experimental results show that the introduction of p-type amorphous CoSnO₃ forms a multi-interface synergistic effect with the SnO₂/Zn₂SnO₄ (n-n heterojunction) substrate, significantly enhancing the gas-sensing performance of the sensor. Specifically, compared with the unmodified SnO₂/Zn₂SnO₄ sensor, the optimal operating temperature of the 0.5 % CoSnO₃/SnO₂/Zn₂SnO₄ sensor was reduced from 380 °C to 320 °C, the lower detection limit was reduced from 1 ppm to 0.5 ppm, and the response value to 100 ppm isopropanol was significantly increased from 40.7 to 490.5, an increase of 12 times. In addition, the sensor exhibits excellent repeatability and long-term stability. The excellent gas-sensing performance of the CoSnO₃/SnO₂/Zn₂SnO₄ sensor prepared in this study mainly stems from its three structural advantages: the effective construction of p–n heterojunctions, abundant surface oxygen vacancies, and the specific adsorption of isopropanol by CoSnO₃. The research team conducted an in-depth and systematic investigation into the gas-sensing mechanism of this composite sensing material.