Hydrogen evolution based on the electrons/protons stored on amorphous TiO.

The hydrogen evolution reaction (HER) using recyclable mediator is being actively pursued as a route for solar energy conversion. Herein, we introduce a catalyst mediator (MoS) that enables proton-coupled electron transfer (PCET) process on the recyclable TiO (H-TiO/e) to a separate, catalytic hydrogen production step without requiring post-light energy input. This approach supplies a new insight to hydrogen evolution with the recyclable proton-electron pairs, stored at the semiconductor after the light irradiation. It was found that 80% of the electrons stored on TiO could be devoted to the reduction of H into H on MoS nanosheets in the dark. The electron transfer to MoS occurs at a rate of 455 μmol h g and 947 μmol h g in the dark and excited state, respectively.