Engineering heterojunction interfaces in porous SnO2/MoO3 composite for highly selective xylene detection

Formation of heterojunction via composite nanomaterials represents a proficient approach for enhancing gas-sensitivity capabilities. In this paper, the design of a xylene sensor based on SnO 2 /MoO 3 heterojunction structure was reported, where mesoporous SnO 2 was prepared utilizing a facile carbon template and then loaded with MoO 3 . The chemical composition, microstructure, and gas-sensing performance of the composite material were systematically characterized and studied. The SnO 2 /MoO 3 sensor achieved a response value of 28.3 at 200 °C for 20 ppm xylene, significantly higher than pure SnO 2 and MoO 3 , with a detection limit reaching 55 ppb. The results indicate that the SnO 2 /MoO 3 composite material significantly enhances sensing response and reduces response/recovery time through its mesoporous structure and n-n heterojunction characteristics. Finally, we focused on analyzing the band structure of the SnO 2 /MoO 3 heterojunction and the xylene sensing mechanism. This work contributes to the study of gas-sensing properties in SnO 2 -based composite materials and provides new insights for real-time and precise detection of xylene.