Fundamental Processes in Surface Photocatalysis on TiO2

Abstract

Due to the potential applications of TiO2 in photocatalytic hydrogen production and pollutant degradation, over the past few decades, we have witnessed the fast-growing interest and effort in developing TiO2-based photocatalysts, improving the efficiency, and exploring the reaction mechanism at the atomic and molecular level. Since surface science studies on single crystal surfaces under UHV conditions could provide fundamental insights into these important processes, both thermal chemistry and photo-chemistry on TiO2, especially on rutile TiO2(110) surface, have been extensively investigated with a variety of experimental and theoretical approaches. In this chapter, we start from the properties of TiO2 and then focus on charge transport and trapping and electron transfer dynamics. Next, we summarize recent progresses made in the study of elementary photocatalytic chemistry of oxygen and methanol on mainly rutile TiO2(110) along with some studies on rutile TiO2(011) and anatase TiO2(101) and (001). These studies have provided fundamental insights into surface photocatalysis as well as stimulated new investigations in this exciting area. At the end of this chapter, implications of these studies for the development of new photocatalysis models are also discussed.