Effective decoration of Pd nanoparticles on the surface of SnO2 nanowires for enhancement of CO gas-sensing performance

Highlights: • Pd nanoparticles decoration on nanowire's surface was done via a simple route. • The size and distribution of Pd nanoparticles was controlled by in situ reduction of the Pd complex. • The coating Pd enhanced capable detection of hazardous CO gas of on-chip growth SnO2 nanowires. • Pd-decorated SnO2 nanowires sensors have good stability to hazardous CO gas. -- Abstract: Decoration of noble metal nanoparticles (NPs) on the surface of semiconducting metal oxide nanowires (NWs) to enhance material characteristics, functionalization, and sensing abilities has attracted increasing interests from researchers worldwide. In this study, we introduce an effective method for the decoration of Pd NPs on the surface of SnO2 NWs to enhance CO gas-sensing performance. Single-crystal SnO2 NWs were fabricated by chemical vapor deposition, whereas Pd NPs were decorated on the surface of SnO2 NWs by in situ reduction of the Pd complex at room temperature without using any linker or reduction agent excepting the copolymer P123. The materials were characterized by advanced techniques, such as high-resolution transmission electron microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The Pd NPs were effectively decorated on the surface of SnO2 NWs. As an example, the CO sensing characteristics of SnO2 NWs decorated with Pd NPs were investigated at different temperatures. Results revealed that the gas sensor exhibited excellent sensing performance to CO at low concentration (1–25 ppm) with ultrafast response-recovery time (in seconds), high responsivity, good stability, and reproducibility