Synthesis\nof Ternary MoS₂/Carbon Dots/ZnIn₂S₄ Nanocomposites for Enhanced Photocatalytic Hydrogen\nEvolution

Abstract

The utilization of solar energy for photocatalytic water\nsplitting\nto generate hydrogen represents a pivotal research domain, with significant\nimplications for ecological and sustainable development. In this investigation,\nwe employed a facile hydrothermal method to synthesize a hierarchical\nflower-like structure comprising a nonprecious metal ternary MoS₂/carbon dots (CDs)/ZnIn₂S₄ heterojunction.\nSpecifically, F-CDs (CDs) and MoS₂ were cultivated on three-dimensional\nZnIn₂S₄ (ZIS) nanoflowers. The photocatalytic\nactivity for hydrogen evolution of the ternary MoS₂/CDs/ZIS\nnanocomposite material surpassed that of MoS₂/ZIS and CDs/ZIS,\nunderscoring a synergistic effect between MoS₂ and CDs\nin facilitating hydrogen evolution. Furthermore, within the ternary\nMoS₂/CDs/ZIS composite material, CDs served as electron\nmediators, expediting the transfer of photogenerated electrons from\nthe semiconductor-based photocatalyst (ZnIn₂S₄) to the cocatalyst (MoS₂). Simultaneously, CDs, functioning\nas electron acceptors, heightened the hydrogen evolution reaction.\nThe hydrogen production of the MoS₂/CDs/ZIS(3) composite\nmaterial reached 13.365 mmol g^–1 within a 5 h duration,\na notable increase of 6.7 times compared to pure ZIS. This investigation\noffers a strategic approach for developing efficient hydrogen evolution\nphotocatalysts by leveraging CDs as a bridge to enhance charge transfer\nin nanocomposite materials.