Enhanced acetone response in co-precipitated WO3 nanostructures upon indium doping

The acetone sensors based on In-doped WO3 nanostructures have been investigated for different operating temperatures and test gas concentrations. The sensor based on 1.5 at% In-doped WO3 nanostructure shows maximum response (∼93%) at the operating temperature of 250 °C for 50 ppm concentration of acetone vapor in air, and also exhibits fast response/recovery time. The XRD results confirm the monoclinic phase of the as-prepared WO3 nanostructures. TEM images reveal that there is an enhancement in the particle size upon indium doping, relative to the undoped WO3. The SEM images exhibit different surface morphology, whereas the EDX spectra confirm the presence of indium ions into the WO3 lattice. Raman spectroscopy studies also confirm the monoclinic structure of the undoped and In-doped WO3 samples.