Highly sensitive and pulse-like response toward ethanol of Nb doped TiO2 nanorods based gas sensors

Highly crystalline TiO2 and 3 wt% Nb-doped TiO2 nanorods were synthesized by a low-temperature surfactant directed hydrolysis method followed by calcination at 600–900 °C. The microstructure and the chemical composition of the thick films were characterized using XRD, SEM, EDX, TEM, XPS, and FTIR. The sensing behavior of TiO2 thick films toward reducing gases (H2, ethanol and LPG) in the temperature range 350–550 °C was studied. Niobium doping retards the anatase to rutile transformation. It was observed that doped TiO2 thick films have an enhanced sensor response compared to the undoped ones. The increased sensor response may be because of presence of anatase phase and the smaller dimension of the nanorods.