Technologically Feasible ZnO Nanostructures for Carbon Monoxide Gas Sensing

Zinc oxide based nanostructures are synthesized on polycore sensor platform with interdigitated contacts by sol-gel and low-temperature hydrothermal method allowing for growth of thin polycrystalline and nanostructured films. The sensor response to the gas exposure was evaluated in terms of resistance. To obtain more efficient response to the atmosphere, ultraviolet lighting conditions were applied. The obtained dependencies allow us to characterize the interaction of nanostructure based on zinc oxide with the carbon monoxide and oxygen. For all of the samples, negligible response to the CO
₂
is demonstrated and positive resistance response is documented under O
₂
exposure. The response of the polycrystalline samples under CO exposure degrades with the quantity of the deposited ZnO which is discussed in terms of the decrease in conductive channels in the planar layer compare to the samples with developed surface. The most efficient CO response is obtained with the sample consisting of ZnO nanowires opening new pathways for fabrication of efficient nanoscale CO gas sensors.