Titanium dioxide (TiO2) has been one of the most studied catalytic systems owing to its broad applications in clean energy and environmental related technologies. One of the central research activities has been devoted to identify and synthesize the highly reactive surface of TiO2.

It was predicted a few years ago by theoretical calculations that the anatase TiO2 (001) surface as well as its reconstructed (1´4) surface should be the “holy” surface with superior catalytic reactivity. This prediction has triggered great interest and motivated many famous synthetic chemists to pursue the synthesis of (001)-rich anatase nanocrystals.

Recently, the researchers in University of Science and Technology of China (USTC) revealed that the perfect surface itself could be fully oxidized, but shows no obvious activity.

According to professor Wang Bing and Zhao Jin from Hefei National Laboratory for Physical Sciences at Microscale in USTC, there are two types of intrinsic point defects on the reduced surface, and only the Ti-rich point defects in the reduced surfaces show considerable chemical activity for water and oxygen molecules.

The reduction treatment history, like the commonly used Ar⁺sputtering and annealing, should be an important factor to determine the reactivity of the surface. The findings can be helpful for a comprehensive understanding of several important issues that are still under debate.

Multipurpose titanium dioxide is reported by foreign media to replace grapheme and become “the most useful chemical material in the world”, especially in the area of new energy. Applications in clean energy and environmental related technologies, such as those in organic solar cells preparation, will accelerate titanium dioxide’s transformation as high-end material in the near future.