Characterizing Photocatalysts -Evaluating their Active States-

It is very important to evaluate the behavior of a photocatalyst in its active state. Performing analyses and evaluations by simulating the environment actually used is referred to as the in-situ method. The term in-situ is from the Latin meaning “at that place.” In the context of catalytic evaluations, it refers to performing measurements either in the actual usage environment or a place where that environment has been recreated. Performing in-situ measurements makes it possible to obtain useful information for understanding the functionality of photocatalysts, and for developing highly efficient photocatalysts.

Understanding the catalytic effect requires understanding the state of the electrons in the catalyst, particularly the state of the electrons at the surface. A scanning probe microscope can be used to visualize the surface potential distribution of the photocatalyst in its excited state.