Efficient and Stable Solar Hydrogen Generation of Hydrophilic Rhenium-Disulfide-Based Photocatalysts Chemically Controlled Charge Transfer Paths.

Effective charge separation and rapid transport of photogenerated charge carriers without self-oxidation in transition metal dichalcogenide photocatalysts are required for highly efficient and stable hydrogen generation. Here, we report that a molecular junction as an electron transfer path toward two-dimensional rhenium disulfide (2D ReS) nanosheets from zero-dimensional titanium dioxide (0D TiO) nanoparticles induces high efficiency and stability of solar hydrogen generation by balanced charge transport of photogenerated charge carriers. The molecular junctions are created through the chemical bonds between the functionalized ReS nanosheets (, -COOH groups) and -OH groups of two-phase TiO (, ReS-CHC(═O)-O-TiO denoted by ReS-BzO-TiO). This enhances the chemical energy at the conduction band minimum of ReS in ReS-BzO-TiO, leading to efficiently improved hydrogen reduction. Through the molecular junction (a Z-scheme charge transfer path) in ReS-BzO-TiO, recombination of photogenerated charges and self-oxidation of the photocatalyst are restrained, resulting in a high photocatalytic activity (9.5 mmol h per gram of ReS nanosheets, a 4750-fold enhancement compared to bulk ReS) toward solar hydrogen generation with high cycling stability of more than 20 h. Our results provide an effective charge transfer path of photocatalytic TMDs by preventing self-oxidation, leading to increases in photocatalytic durability and a transport rate of the photogenerated charge carriers.