Efficient and Stable Solar-Hydrogen Generation of Hydrophilic Rhenium Disulfide-Based Photocatalysts via 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 ReS2) nanosheets from zero-dimensional titanium dioxide (0D TiO2) 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 ReS2 nanosheets (e.g., –COOH groups) and –OH groups of two-phase TiO2 (i.e., ReS2–C6H5C(=O)–O–TiO2 denoted by ReS2–BzO–TiO2). This enhances the chemical energy at the conduction band minimum of ReS2 in ReS2–BzO–TiO2, leading to efficiently improved hydrogen reduction. Via the molecular junction (a Z-scheme charge transfer path) in ReS2–BzO–TiO2, recombination of photogenerated ch...