Synchronizing periodic excitations of photocatalysts with a Michelson interferometer on operando FT–IR spectroscopy, researchers led by Toshiki Sugimoto succeeded in observing and identifying the reactive electron species for photocatalytic hydrogen evolution. In contrast to previous assumptions, this study demonstrates that it is not the free electrons in metal cocatalysts but the electrons trapped in the periphery of cocatalysts that directly contribute to the photocatalysis.
