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

Abstract

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 2 ) nanosheets from zero-dimensional titanium dioxide (0D TiO 2 ) 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 2 nanosheets (e.g., −COOH groups) and −OH groups of two-phase TiO 2 (i.e., ReS 2 −C 6 H 5 C(O)− O−TiO 2 denoted by ReS 2 −BzO−TiO 2 ). This enhances the chemical energy at the conduction band minimum of ReS 2 in ReS 2 −BzO−TiO 2 , leading to efficiently improved hydrogen reduction. Through the molecular junction (a Z-scheme charge transfer path) in ReS 2 −BzO−TiO 2 , recombination of photogenerated charges and self-oxidation of the photocatalyst are restrained, resulting in a high photocatalytic activity (9.5 mmol h −1 per gram of ReS 2 nanosheets, a 4750-fold enhancement compared to bulk ReS 2 ) 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.

A Tandem 0D/2D/2D NbS2 Quantum Dot/Nb2O5 Nanosheet/g‐C3N4 Flake System with Spatial Charge–Transfer Cascades for Boosting Photocatalytic Hydrogen Evolution

“…[16][17][18] Moreover, transition metal dichalcogenides (simplified as MX 2 , M = transition metal; X = S, Se, Te) have aroused keen interests due to their excellent electronic and optical properties, low cost and high aspect ratio. [19][20][21] In the community of MX 2 , group-5 MX 2 materials represented by NbS 2 have massive highly active basal-plane sites, which enable them to be the promising cocatalysts for photocatalytic H 2 evolution. [22][23][24] Therefore, in view of the advantages of 0D quantum dot structure and NbS 2 , selectively loading NbS 2 QDs as the cocatalyst C on the surface of Nb 2 O 5 in the 2D/2D Nb 2 O 5 /g-C 3 N 4 B/A-typed heterojunctions is to construct a unique tandem 0D/2D/2D system (Figure 1b), which can create numerous spatial charge-transfer cascades from 2D g-C 3 N 4 to active-site-rich NbS 2 QDs via 2D Nb 2 O 5 , thus leading to significantly enhanced charge-transfer efficiency and high photocatalytic H 2 evolution activity.…”

Understanding Surface Modulation to Improve the Photo/Electrocatalysts for Water Oxidation/Reduction

“…For example, molecules with increased magnitudes of aromaticity induce increased surface dipoles [100]. In addition, porphyrine and phthalocyanine moieties can inserted in the solid-solid junction to modulate the charge transfer at the interface [101,102]. These kinds of molecules are modulated by the various metal cation coordination and precisely tune the interface charge transfer.…”

A Review of MOFs and Their Composites‐Based Photocatalysts: Synthesis and Applications

“…Up to now, many different types of functional nanomaterials, including metal oxides, [ 2–5 ] metal phosphides, [ 6–8 ] metal sulfides [ 9–12 ] as well as carbon‐based composites [ 13–15 ] have been synthesized and utilized as the photocatalysts for energy conversion systems. However, photocatalysts based on these materials still face some challenges, such as the low electronic conductivity and poor apparent quantum efficiency of the metal oxides‐based photocatalysts, [ 1 ] rapid recombination of the charge carries of the metal phosphides‐based photocatalysts, [ 6 ] the poor chemical stability of the metal sulfides‐based photocatalysts, [ 10 ] poor cycling stability of the carbon materials‐based photocatalysts. [ 14,15 ] Thus, the construction of superior functional materials with outstanding overall photocatalytic performances is highly desirable.…”