A Tandem 0D/2D/2D NbS2 Quantum Dot/Nb2 O5 Nanosheet/g-C3 N4 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 NbS2 quantum dot/Nb2 O5 nanosheet/g-C3 N4 flake (NSNOCN) system is designed. Owing to the unique spatial-arrangement and elaborate morphology of 0D NbS2 , 2D Nb2 O5 , and 2D g-C3 N4 in the newly designed NSNOCN, plenty of spatial charge-transfer cascades from g-C3 N4 to NbS2 via Nb2 O5 are formed to accelerate separation and transfer of charges significantly, thus contributing to a high photocatalytic H2 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-C3 N4 and Nb2 O5 , respectively. This work can provide a new platform in the design of artificial photocatalytic systems with high charge-transfer efficiency.