Anchoring Pd nanoparticles on metal-organic frameworks for SO2 detection

Enhancing the electron transport capability of metal-organic framework (MOF) materials, which are novel gas sensing materials, remains a formidable challenge. In this study, palladium metal nanoparticles (Pd-NPs) were successfully anchored on the surface of ZIF-8, a porous material, by using chemical reduction to improve the gas sensing performance of ZIF-8 significantly. The active catalytic sites of Pd-NPs are stimulated by the porous structure of ZIF-8 and are uniformly dispersed on the surface of the porous ZIF-8 material. The Pd-NPs/ZIF-8 composite material has good response and selectivity for up to 200 ppm SO2 at 300 degrees C (gas sensing response of 86.61%), a fast response time (approximately 24 s), low detection limit (4.0 ppb) and excellent stability and anti-interference ability. These outcomes can be attributed to the fact that anchoring Pd-NPs on the surface of the porous ZIF-8 material can effectively improve gas sensing performance by exploiting the high conductivity and catalytic activity of Pd-NPs through electron and chemical sensitisation.