MnO2 enhanced low temperature HCHO sensing performance of SnO2

The exploration of gas sensing materials holds significant importance for practical applications. This work introduces a novel SnO2/MnO2 nanocomposite designed to achieve formaldehyde monitoring at ppb level with a relative low temperature. The as prepared sensor demonstrates a response of 8.1 to 50 ppb formaldehyde at 100 oC. These remarkable formaldehyde sensing capabilities were explained by the heterojunction structure of the composite, and the low-temperature catalytic properties of MnO2. Moreover, in-situ infrared reflectance spectroscopy was employed to investigate the underlying mechanism by monitoring the evolution of reaction intermediates, and the result suggested that the addition of MnO2 can reduce the ineffective occupation of active sites and promote the generation of intermediate intermediates.