Study the properties of Ball-Milled Vanadium Oxide Powders for Gas Sensor Applications

In this study, the vanadium oxide powders were ball-milled at different milling times. The basic characterization for analyzing the properties of vanadium oxide samples and their sensing properties for carbon oxide were mainly studied. XRD results confirmed the formation of the orthorhombic crystal structure of V
2
O
5
by comparing the presence of peaks. Three dominant peaks, such as (001), (110), and (400), are found for both with and without ball-milled vanadium oxide samples. The crystallite sizes for vanadium oxide are varying from 12 to 20 nm. From the Raman spectra, the peaks at wavenumbers at around 142, 196, 287, 407, 524, 690, and 995 cm
^-1
are also related to the orthorhombic crystal structure of V
2
O
5
. The nanoclusters with irregular morphologies are seen from the SEM images. The compositions of vanadium atoms enhance with a rise in milling times. Symmetrical compositions of vanadium and oxygen atoms are observed for vanadium oxide powder milled at 9 hours. High absorption spectra are found for light having a wavelength ranging from 300 to 500 nm. The bandgaps of vanadium oxide samples are calculated using reflection spectra through the Kubelka-Munk theory. The bandgap values of vanadium oxide samples after ball milling are lower (i.e., less than 2.9 eV) than without ball milling. The sensing response of the ball-milled VO samples against a carbon monoxide gas are determined by analyzing the electrical resistances.