Highly sensitive CO sensor based on Al-doped-ZnO nanorods-coated resonant microcantilevers

Abstract

A highly sensitive (at the picogram order) Al-doped-ZnO nanorods (AZNRs)-coated resonant microcantilever (MC) for carbon monoxide (CO) gas sensing, operable at ambient temperature and under humid condition was synthesized. The ZnO nanorods were grown on the MC surface by using the hydrothermal method and doped by aluminum (Al). The sensitivities of un-doped and AZNRs for various CO gas concentrations were investigated by measuring the changes in the resonant frequencies and the Q-factor analysis of the vibrating MCs. The mechanisms of the remarkable enhancement of the sensitivity of the AZNRs-coated-microcantilever to CO were thoroughly investigated and discussed on the basis of energy gap between the highest occupied molecular orbital-lowest occupied molecular orbital of AZNRs and CO, active surface area of AZNRs, and the interaction of water vapor on AZNRs surface with CO.

CO oxidation mediated by Al‐doped ZnO nanoclusters: A first‐principles investigation

“…Hence, understanding the surface reactivity and catalytic properties of small ZnO clusters and their assembled nanowire structures may help in the characterization of their sizedependent active sites. Furthermore, due to the high sensitivity of Al incorporated ZnO nanostructures to CO molecule [9,[56][57][58], these systems are expected to be active catalysts for converting CO into CO 2 . Hence, the current work attempts to investigate the feasibility of employing Al-doped Zn 12 O 12 monomer and its assembled wire-like structures as noble metal-free catalysts for CO oxidation.…”