The hierarchical nanostructured Co-doped WO3/carbon and their improved acetone sensing perfomance. (October 2020)

• Record Type: Journal Article
• Authors: Saasa, Valentine; Malwela, Thomas; Lemmer, Yolandy; Beukes, Mervyn; Mwakikunga, Bonex
• Is Part Of: Materials science in semiconductor processing. Volume 117(2020)
• Publication Date: 2020-10
• Subjects: Acetone -- Cobalt doped tungsten oxide -- Sensor -- Metal oxides -- Semiconductor -- Sensitivity; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105157
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Hierarchical nanostructured Co-doped WO3 with carbon as template has been successfully synthesised through facile sol-gel method. The synthesised Co-doped WO3 was characterized by X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy, Energy dispersive X-ray spectrometry, and Brunauer-Emmett-Teller and X-ray photoelectron spectroscopy. The gas sensing properties of WO3 doped with Co from 0 to 0.8 wt % were also investigated on various VOCs. The fabricated sensor based on 0.6 wt% Co-doped WO3 with carbon as a template showed good sensitivity, selectivity, fast response and recovery time towards 1.5 ppm of acetone at 50 °C under 90% relative humidity. The excellent gas sensing properties could be attributed to high surface area, small crystallite size, defect of WO3 and Co catalysis effect which promotes gas adsorption and most importantly the stabilized monoclinic phase of WO3, which accounts for the good selectivity. Highlights: Gas sensing Co-doped WO3 hierarchical nanostructures with carbon nanospheres as a template were prepared via Sol-gel method. Co doping and carbon template increases WO3 surface area. 0.6 wt % Co-WO3 with carbon template showed highest response and selectivity towards 1.5 ppm of acetone. Highest selectivity to acetone detection at lowest temperature among sensing materials. Highest response at lowest operating temperature of all WO3 materials.