Quartz crystal microbalance sensor for NO2 detection based on electrospun amorphous titanium oxide fibers

Abstract

Abstract The sensitivity to various concentrations of NO2 is studied of a 16-MHz quartz crystal microbalance (QCMs) coated by immobilized electrospun amorphous titanium oxide fibers. The morphology, phase and chemical composition of the sensing material are determined by scanning and high-resolution transmission electron microscopy (SEM, HRTEM), transmission high-energy electron diffraction (THEED) and X-ray photoelectron spectroscopy (XPS). Resonance frequency shifts are established of the QCM-TiO2 system within a broad interval of NO2 concentrations. Experimental evidence is found for a reversible gas sorption at the lowest tested gas concentration of 50 ppm. Additional sensor response is established to gradually increasing NO2 concentrations up to 5000 ppm. It is demonstrated that electrospun amorphous titanium oxide fibers are promising sensing materials for NO2 detection.