UV Enhanced NO2 sensing properties of Pd-functionalized WO3 nanorods

초록

WO3 one-dimensional (1D) nanostrutures were synthesized by using a thermal evaporation technique. The morphology, crystal structure, and sensing properties of the WO3 nanostructures functionalized with Pd to NO2 gas at room temperature under UV irradiation were examined. The diameters of the 1D nanostructures ranged from a few tens to a few hundreds of nanometers and the lengths ranged up to a few hundreds of micrometers. Pd nanoparticles with diameters of a few tens of nanometers were distributed around a WO3 nanorod. The responses of the nanorods gas sensors fabricated from multiple networked WO3 nanorods were improved 2-3 fold at NO2 concentrations ranging from 1 to 5 ppm by Pd functionalization. The Pd-functionalized WO3 nanorod gas sensors showed a remarkably enhanced response at room temperature under ultraviolet (UV) light illumination. In addition, the mechanisms via which the gas sensing properties of WO3 nanorods are enhanced by Pd functionalization and UV irradiation are discussed.