Vertical Mode Gas Sensing Performance of TiO 2 Nanotube Array by Tuning of Surface Area and Carrier Transport Length

摘要: 1-D oxide nanostructures-based metal-insulator–metal structures represent potential gas sensor devices, owing to their vertical electron transport feature. In this paper, we demonstrate that for achieving optimum sensing by a TiO2 nanotube (NT) array in mode, tuning of NTs (1-D) surface area as well carrier path length tailoring the NT can be valuable approach. For anodization times 1, 4, 8, 12, and 16 h, corresponding was found 280–320, 506–514, 1730–1790, 2000–2200, 2380–2420 nm, respectively, with almost no variation tube diameters or separations. The concentrations were decreasing increasing length. device structure, employing arrays different lengths layer, investigated temperature range 50 °C–250 °C acetone, test gas/vapor, concentration 10–1000 ppm. response magnitude increased length, possibly availability larger amounts interaction sites due higher at time recovery developed also became excessively sluggish after critical exceeded 2250 nm slower adsorption/desorption diffusion kinetics.