Efficient zinc oxide nanostructures for enhanced ethanol sensing and photocatalytic applications

Zinc oxide (ZnO) nanostructures were synthesized through a hydrothermal method using zinc nitrate hexahydrate and citric acid as precursors with subsequent heat treatment at 80 °C.The ZnO nanostructures were characterized by XRD, revealing a hexagonal wurtzite structure typical of ZnO, with sharp diffraction peaks confirming high crystallinity and purity.Vibrational properties assessed by Raman spectroscopy indicated typical ZnO phonon modes, while photoluminescence and UV-visible spectroscopy analyses demonstrated effective crystallinity and a band gap energy of 2.89 eV, important for optoelectronic applications.Microscopic analysis provided insights into the uniform morphology of the nanostructures.Additionally, these ZnO nanostructures were employed as sensing electrode for ethanol detection; showing the enhanced electron transfer capabilities and high sensitivity of 167.98 μA.mM⁻¹cm⁻² within the ethanol concentration range of 10 to 100 μM.Stability tests confirmed the sensor’s reliability over two weeks.The proposed sensing mechanisms include the interaction of ethanol with chemisorbed oxygen species on ZnO, facilitating electron transfer.The study also explored the photocatalytic degradation of methylene blue under UV light, where the nanostructures achieved significant dye breakdown, attributed to the generation of reactive oxygen species.These findings highlight the multifunctional applications of ZnO nanostructures in sensors and environmental remediation.