Pd-loaded In2O3 nanowire-like network synthesized using carbon nanotube templates for enhancing NO2 sensing performance

Pd-loaded In2O3 nanowire (NW)-like networks were synthesized via electroless plating using carbon nanotubes (CNTs) as templates, followed by oxidation and removal of the CNTs at 550 degrees C. Palladium (Pd) was introduced to activate the surface of the CNTs for subsequent plating. Before calcination, Pd was loaded onto In2O3. The as-synthesized Pd-loaded In2O3 replicated the structure of the CNTs, forming a porous NW-like network with a very large specific surface area. Furthermore, the NO2 gas sensing properties of the Pd-loaded In2O3 NW-like network, porous Pd-In2O3 and porous unloaded-In2O3 were investigated. The results demonstrated that the Pd-In2O3 NW-like network exhibits superior sensitivity with short response and recovery times, and demonstrates a significant response when exposed to NO2 at concentrations as low as 5 ppm at a temperature of 110 degrees C. A synergy of electric and chemical effects has been proposed to explain the gas sensing enhancement.