LAUSR

A novel double-layer TiO2 nanorod arrays (NRAs) gas sensor for room-temperature detection of NH3 was fabricated by employing the etched fluorine-doped tin dioxide (FTO) glass as the in-situ growing substrate and the new-type gas-sensing electrode via the facile droplet-coating and hydrothermal methods. Due to the synergistic effect of forces, the special double-layer TiO2 NRAs with the cross-linked and bridge-like structure is formed, in which the adequate point junctions can be generated to construct the self-assembled electron pathways required for gas-sensing tests. Gas-sensing tests indicate all samples obtained at different growth times have an excellent gas-sensing response to low-concentration NH3 at room temperature. Among them, the TiO2 NRAs obtained at 6 h (S2) exhibit the highest gas-sensing response to 100 ppm NH3 with a value of 102%. In addition, the growth mechanism, the gas reaction mechanism and the effect of humidity on the gas-sensing performance are also discussed in the present paper.