Synthesis of Ternary MoS₂/Carbon Dots/ZnIn₂S₄ Nanocomposites for Enhanced Photocatalytic Hydrogen Evolution

Abstract

The utilization of solar energy for photocatalytic water splitting to generate hydrogen represents a pivotal research domain, with significant implications for ecological and sustainable development. In this investigation, we employed a facile hydrothermal method to synthesize a hierarchical flower-like structure comprising a nonprecious metal ternary MoS2/carbon dots (CDs)/ZnIn2S4 heterojunction. Specifically, F-CDs (CDs) and MoS2 were cultivated on three-dimensional ZnIn2S4 (ZIS) nanoflowers. The photocatalytic activity for hydrogen evolution of the ternary MoS2/CDs/ZIS nanocomposite material surpassed that of MoS2/ZIS and CDs/ZIS, underscoring a synergistic effect between MoS2 and CDs in facilitating hydrogen evolution. Furthermore, within the ternary MoS2/CDs/ZIS composite material, CDs served as electron mediators, expediting the transfer of photogenerated electrons from the semiconductor-based photocatalyst (ZnIn2S4) to the cocatalyst (MoS2). Simultaneously, CDs, functioning as electron acceptors, heightened the hydrogen evolution reaction. The hydrogen production of the MoS2/CDs/ZIS(3) composite material reached 13.365 mmol g–1 within a 5 h duration, a notable increase of 6.7 times compared to pure ZIS. This investigation offers a strategic approach for developing efficient hydrogen evolution photocatalysts by leveraging CDs as a bridge to enhance charge transfer in nanocomposite materials.