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 MoS 2 /carbon dots (CDs)/ ZnIn 2 S 4 heterojunction. Specifically, F-CDs (CDs) and MoS 2 were cultivated on three-dimensional ZnIn 2 S 4 (ZIS) nanoflowers. The photocatalytic activity for hydrogen evolution of the ternary MoS 2 /CDs/ZIS nanocomposite material surpassed that of MoS 2 /ZIS and CDs/ZIS, underscoring a synergistic effect between MoS 2 and CDs in facilitating hydrogen evolution. Furthermore, within the ternary MoS 2 /CDs/ZIS composite material, CDs served as electron mediators, expediting the transfer of photogenerated electrons from the semiconductor-based photocatalyst (ZnIn 2 S 4 ) to the cocatalyst (MoS 2 ). Simultaneously, CDs, functioning as electron acceptors, heightened the hydrogen evolution reaction. The hydrogen production of the MoS 2 /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.