Metal oxides are frequently used in various forms of catalysts. Among them, TiO2 is a representative oxide system which is widely used as a photocatalyst as well as a thermal catalyst. In addition, WO3 is also a widely studied material in various applications as catalysts and sensors due to its facile redox properties associated with its color changes. Based on this motivation, we fabricated TiO2–or WO3–based oxide systems through hydrothermal and plasma-assisted methods and studied catalytic reactivity in relation to its surface properties. In addition, to extend our study toward an understanding on how to enhance catalytic properties of these functional materials, we also studied the characteristics of N2 plasma and employed the afterglows of the N2 plasma for surface modification of TiO2 films. Finally, we have applied our present understanding on the role of oxide catalysts and plasma into the development of a new one-step catalytic process for the catalytic conversion of methane into methanol, which is at the heart of C1 chemistry.
