Abstract:

Chiral photocatalysts show significant promise for photocatalytic hydrogen evolution. However, chirality-regulated cadmium sulfide (CCdS) continues to suffer from insufficient photogenerated charge separation, which restricts its practical application and further advancement. Herein, we construct a novel Schottky heterojunction photocatalyst (CCdS/CTC) composed of CCdS and Co-doped Ti₃C₂ (CTC) via a simple physical mixing method. Notably, the photocatalyst achieves a hydrogen yield of 21937 μmol g⁻¹ from polylactic acid (PLA) microplastics within 5 h, accompanied by simultaneous conversion of PLA into pyruvic acid (PA) small molecules. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations demonstrate the interfacial charge transfer between CCdS and CTC upon contact, and in situ XPS confirms the charge transfer under illumination. Photoelectrochemical measurements demonstrate that the chirality regulation of CCdS works synergistically with the constructed heterojunction to effectively promote photogenerated charge separation and transport. The Schottky heterojunction formed at the CCdS/CTC interface further enhances the photogenerated carrier separation efficiency of CCdS. The synergy between chirality regulation and elemental doping markedly suppresses photogenerated charge recombination and optimizes surface reaction kinetics. This work presents a promising approach for converting plastic waste into H₂ fuel, offering critical insights into the rational design of sustainable photocatalysts for environmental remediation and renewable energy production.

Key words: Chiral control, CdS, MXene, Schottky heterojunction, Microplastic hydrogen production