High sensitivity and fast response sensor for formaldehyde based on In2O3/Sn2O3 heterojunction

Abstract

Modifying metal oxide semiconductor materials is a primary approach to enhance gas sensor performance, and heterojunction is a promising method to address cross-sensitivity issues in gas sensors. Sn2O3 nanoflower-based substrates and In2O3/Sn2O3 heterojunction structures were successfully synthesized by hydrothermal synthetic method. The gas-sensing performance of the In2O3/Sn2O3 heterojunction-based gas sensor towards formaldehyde gas was investigated. The gas sensor based on In2O3/Sn2O3 heterojunction exhibited higher sensitivity to formaldehyde gas compared to pure Sn2O3 gas sensor at the same operating temperature. The response and recovery rates of the sensor were significantly improved as well. In addition, the In2O3/Sn2O3 gas sensor exhibited lower response to interfering gases compared to its response to formaldehyde gas, thus demonstrating superior selectivity over the pure Sn2O3 sensor. The result provides a research direction for the development of high-performance, highly selective, and rapid response formaldehyde sensors, which has certain reference significance for the advancement of gas sensor technology.