Quantum Confinement Effect in MoC QDs/CdIn₂S₄ Schottky Junction to Achieve Efficient Photocatalytic Hydrogen Evolution

Owing to the quantum confinement effect, quantum dots (QDs) achieve improved charge transfer efficiency, leading to a remarkable enhancement in photocatalytic hydrogen production activity. In this work, a MoC/CdIn2S4 Schottky junction photocatalyst was fabricated using the electrostatic self-assembly method. Moreover, the quantum confinement effect significantly reduces the charge transfer resistance, thereby improving the overall charge transfer efficiency. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations reveal that electrons transfer from CdIn2S4 to MoC, accumulating at the interface to form a built-in electric field. Meanwhile, under the synergistic effect of the built-in electric field and Schottky barrier, the separation efficiency of photogenerated electron–hole pairs is significantly enhanced, thereby significantly improving the photocatalytic hydrogen evolution. The optimized 3-MoC/CdIn2S4 photocatalyst exhibits outstanding hydrogen production performance, achieving a rate of 12.69 mmol·g–1·h–1, which is 6.55 times higher than that of CdIn2S4 alone. This research offers novel insights into the design principles and mechanisms of quantum dot-based heterojunctions applied in photocatalytic hydrogen evolution.