High-performance ethanol gas sensor based on CeO2/Zn2SnO4 heterojunction composites

In this study, CeO 2 /Zn 2 SnO 4 composites were synthesized via a facile and efficient two-step hydrothermal method. The crystal structure, surface chemical composition, and morphology of the prepared materials were systematically characterized using XRD, XPS, SEM, and TEM. Gas sensors were fabricated using these materials and evaluated for their potential application in ethanol detection. The gas sensing properties of the CeO 2 /Zn 2 SnO 4 composites toward various volatile organic compounds (VOCs) were investigated in the temperature range from 100 to 380 °C. The experimental results demonstrate that the Zn 2 SnO 4 -based sensor modified with 15 mol% CeO 2 exhibits outstanding sensing performance toward 100 ppm ethanol. In particular, the sensor shows excellent selectivity compared with other interfering VOCs and achieves optimal sensing performance at 180 ℃. Under this condition, the response value reaches 308.5, and the response time is approximately 17 s, indicating a fast and highly sensitive detection capability. The improved performance of this ethanol sensor is primarily attributed to the formation of the CeO 2 –Zn 2 SnO 4 heterojunction and the increase in oxygen vacancies.