PtS quantum dots/Nb2O5 nanosheets with accelerated charge transfer for boosting photocatalytic H2 production

The rapid recombination rate of charges limits the improvement of photocatalytic hydrogen evolution performance related to semiconductor photocatalysts. An effective strategy to accelerate charge separation and transfer is the design and construction of new high-efficiency cocatalysts on photocatalysts. Herein, a system of PtS quantum dots/Nb2O5 nanosheets (PtS/Nb2O5) was constructed via the in situ vapor phase (ISVP) synthesis process. The conclusions from ultrafast femtosecond-resolved TA spectroscopy indicated that the lifetime of the photogenerated charges of PtS/Nb2O5 (6073.75 ps) was shortened markedly in contrast to that of Nb2O5 (6634.05 ps), manifesting the facilitated separation and transfer of photogenerated charges caused by the quantum-dot-structured PtS cocatalyst. The enhanced charge separation and transfer capacity contributes to an excellent H2 production rate of 182.5 μmol h-1 for PtS/Nb2O5, which is up to 3.4 and 12.2 times that of Pt/Nb2O5 and Nb2O5, respectively. This work brings up new avenues for constructing unique and effective photocatalysts via the cocatalyst design.