This work presents a novel nanostructured material SnO2/multiwalled carbon nanotubes (MWCNTs) as a sensing film for the detection of acetone and ethanol vapors. The fabrication of SnO2/MWCNT chemoresistive sensors demonstrates a cost-effective hydrothermal method using a centrifugation technique. The material investigation of the synthesized SnO2/MWCNTs nanocomposite represents various techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) elementary analysis, EDX mapping, and X-ray diffraction (XRD) analysis. The SnO2/MWCNTs sensor exhibits rapid response/recovery behavior toward acetone (53/5 s) and ethanol (86/3 s) while showing satisfactory values of responsiveness (S act = 90.5 and S etn = 21, n = 100 ppm). The low detection limit of these vapors is assigned a concentration of 1 ppm, where discernible responses are elicited. Thus, the SnO2/MWCNTs sensor production efforts have yielded a high-end volatile organic compound (VOC) detector, highly suitable for human technological and engineering activity.

• Publikační typ
• časopisecké články MeSH

Zinc oxide rod structures are synthetized and subsequently modified with Au, Fe2O3, or Cu2O to form nanoscale interfaces at the rod surface. X-ray photoelectron spectroscopy corroborates the presence of Fe in the form of oxide-Fe2O3; Cu in the form of two oxides-CuO and Cu2O, with the major presence of Cu2O; and Au in three oxidation states-Au3+, Au+, and Au0, with the content of metallic Au being the highest among the other states. These structures are tested towards nitrogen dioxide, ethanol, acetone, carbon monoxide, and toluene, finding a remarkable increase in the response and sensitivity of the Au-modified ZnO films, especially towards nitrogen dioxide and ethanol. The results for the Au-modified ZnO films report about 47 times higher response to 10 ppm of nitrogen dioxide as compared to the non-modified structures with a sensitivity of 39.96% ppm-1 and a limit of detection of 26 ppb to this gas. These results are attributed to the cumulative effects of several factors, such as the presence of oxygen vacancies, the gas-sensing mechanism influenced by the nano-interfaces formed between ZnO and Au, and the catalytic nature of the Au nanoparticles.

• Klíčová slova
• Schottky junctions, copper oxide, gas sensing, gold, heterojunctions, interfaces, iron oxide, nitrogen dioxide, zinc oxide,
• Publikační typ
• časopisecké články MeSH