Cu- and Co-added TiO2 sensing material composites were prepared by oxidizing TiN-Cu and TiN-Co composites that were synthesized using ball milling in an N2 atmosphere. Structural characterization was performed using X-ray diffraction, field emission scattering electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The pure, Co- and Cuadded TiO2 sensing materials were prepared by oxidizing the synthesized TiN, TiN-Cu and TiN-Co powders at 600 oC. The additive Cu in the TiO2 powder was changed to CuO crystals while the additive Co formed the CoTiO3 phase. Therefore, the CuO phase was segregated and grown regardless of the TiO2, however the additive Co in the TiO2 was not cohered. The Coadded TiO2 had greater responses than that of the Cu-added sample at all operating temperatures and showed the highest response of 5.32 at 1000 ppm CO gas. The higher sensing response of the Co-added TiO2 resulted in an enhancement of the grain surface and incorporation with catalytic metals by highly dispersed Co.

Keywords: Composites, Nanostructured materials, Mechanical milling, TiO2 sensor material, Metal oxide semiconductor