Cu-TiH2 and Cu-TiN powders were synthesized using a ball milling process under pressurized H2 and N2 atmospheres,respectively. Cu-TiO2-h and Cu-TiO2-n sensing materials were prepared by oxidizing the synthesized Cu-TiH2 and Cu-TiNpowders at 600 oC. The mean size of the Cu-TiN particles (34.5 nm) was much smaller than that of Cu- TiH2 powder(106.1 nm). The TiH2 phase of the Cu-TiH2 powder entirely changed to a rutile phase while Cu-TiO2-n powder consisted ofboth anatase and rutile phases. The Cu-TiO2-n device had higher responses than the others at all CO concentrations andoperating temperatures of 250-450 oC. The Cu-TiO2-n powder exhibited an anatase phase and a larger surface area than theCu-TiO2-h powder. Additionally, the Cu-TiO2-n powder had a microstructure with well dispersed CuOx. Therefore, it isbelieved that the mechanical nitrifying process is more effective to enhance the sensing performance of Cu-TiO2 to CO gas.

Keywords: Nitrifying process, Oxidation of nitride and hydride, TiO2 material, Metal oxide semiconductor