A Tandem 0D/2D/2D NbS 2 Quantum Dot/Nb 2 O 5 Nanosheet/g-C 3 N 4 Flake System with Spatial Charge-Transfer Cascades for Boosting Photocatalytic Hydrogen Evolution.

The relatively high recombination rate of charges remains the most critical limiting factor for solar-driven water splitting for hydrogen generation. Herein, a tandem 0D/2D/2D NbS ₂ quantum dot/Nb ₂ O ₅ nanosheet/g-C ₃ N ₄ flake (NSNOCN) system is designed. Owing to the unique spatial-arrangement and elaborate morphology of 0D NbS ₂ , 2D Nb ₂ O ₅ , and 2D g-C ₃ N ₄ in the newly designed NSNOCN, plenty of spatial charge-transfer cascades from g-C ₃ N ₄ to NbS ₂ via Nb ₂ O ₅ are formed to accelerate separation and transfer of charges significantly, thus contributing to a high photocatalytic H ₂ generation rate of 13.99 mmol h ^-1 g ^-1 (an apparent quantum efficiency of 10.8% at 420 nm), up to 107.6 and 43.7 times by contrast with that of g-C ₃ N ₄ and Nb ₂ O ₅ , respectively. This work can provide a new platform in the design of artificial photocatalytic systems with high charge-transfer efficiency.
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