Probing Intra‐Gap States Mediated Charge Dynamics of Rh‐Doped Rutile TiO2 Photocatalyst by Light‐Modulated Photocurrent Spectroscopies

The intra-gap states that are introduced into a semiconducting photocatalyst via dopants and other defects have significant implications on the transport dynamics of photoexcited electrons and holes during an aqueous light-driven reaction. In this work, mechanistic understanding of Rh-doped rutile, a promising photocatalyst for hydrogen production from water, is gained by systematic assessment combining intensity-modulated photocurrent spectroscopy with sub-gap excitations and alternating-current photocurrent spectroscopy. These operando techniques not only help in discovering a new electronic transport path in Rh-rutile via surface Rh