LAUSR

Pure and zinc-doped CdO nanoparticles were synthesized via a novel microwave combustion method. The structural, morphology, chemical composition and optical properties of the samples were systematically investigated. The powder x-ray diffraction patterns reveal that both pure and doped samples are of a single crystalline nature with a cubic Fm3m CdO structure. Spherical-shaped morphology with an average diameter of around 25–35 nm was observed by field emission scanning electron microscope analysis. Optical studies showed that Zn2+-doped CdO decreases the band gap energy (Eg) from 3.42 eV to 3.12 eV. The sensor was produced via an extremely simple process in which Zn-CdO powders were deposited directly into an interdigital electrode immersed in a chemical bath under ambient conditions. The proposed sensor showed almost linear behavior within a chosen range of humidity (between 10% and 90% RH) and fast response (25 s) and recovery time (20 s). Our reproducible experimental results exhibited that Zn-doped CdO nanoparticles have a great potential for humidity-sensing applications in room temperature operations. The samples were further investigated for their photocatalytic activity by degradation of Rhodamine B and Methyl orange under UV light irradiation. The improved photocatalytic mechanism by Zn doping is also discussed in detail.