RESUMO
Interlinked ribbon-like TiO2 films were prepared by micro-arc oxidation (MAO) process and subsequent chemical-treatment of titanium substrate. The chemical-treatment included two steps: firstly, alkali treatment was performed on the surface of the porous TiO2 films, and then the samples were ion-exchanged in acid aqueous solution. The phase and microstructure of the samples were characterized by XRD, FE-SEM and TEM. It is found that ribbon-like sodium titanate is formed by alkali treatment, and its morphology remains unchanged after acid-treatment. However, the phase compositions of the samples surface change into TiO2 (MAOC-TiO2) after heat-treatment above 500 degrees C. The hydrogen sensing properties at low concentrations were investigated. The result shows that such ribbon-like TiO2 films present high sensing properties at a low temperature.