Anchoring MoS₂ microflowers on oxygen-doped g-C₃N₄ nanosheets to construct Z-scheme hybrid composites for photocatalytic hydrogen production

Fabricating carbon nitride (g-C₃N₄) based photocatalysts with high visible-light utilization efficiency and rapid photogenerated carrier migration rate is crucial for the improvement of photocatalytic hydrogen production. Herein, we designed and prepared Z-scheme O-CNS/MoS₂ hybrid composites via a two-step combining with ultrasound sonication method. The obtained O-CNS/MoS₂ composites possessed boosting visible-light absorption capacity, revealed by the results of the diffused reflectance spectra (DRS). In contrast to bulk g-C₃N₄ (u-CNB) and O-CNS samples, the obtained O-CNS/MoS₂ composites displayed significantly enhanced photocatalytic hydrogen behavior. Specifically, the O-CNS/MoS₂ photocatalysts with 5 wt% loading of MoS₂ exhibited the highest hydrogen production rate (HPR), which was respectively 26.5 and 1.97 times bigger than that of u-CNB and O-CNS sample correspondingly. This promoted photocatalytic hydrogen behavior was plausibly attributed to the synergistic effect of the porous structure, improved light absorption capacity, and enhanced photoactivated carrier migration rate. Based on comprehensive analysis, the migration and separation pathway of photoactivated carriers were proposed for interpreting the enhancement mechanism of the photocatalytic hydrogen behavior. Our work will open up an innovative strategy for the design and construction of novel g-C₃N₄ hybrid photocatalysts with boosting photocatalytic hydrogen production behavior.