Green Energy & Environment: Ti3C2 MXene Quantum Dots Build Dual-Defect S-Scheme Junction for H2 Coupled with PPCP Degradation

In April 2026, the Green Energy & Environment journal published a study on quantum-dot-mediated dual-defect interface engineering (first author: Zhu Haida; corresponding authors: Wang Anqi, Wang Hui and Chang Zhaofeng; DOI: 10.1016/j.gee.2026.04.011).

1. The Problem

Conventional CeO2/MoS2 heterostructures tend to suffer from MoS2 nanosheet stacking and severe carrier recombination - like a highway jamming right after it opens, where photogenerated electrons and holes vanish before participating in reactions. Meanwhile, conventional H2 production relies on precious metals and sacrificial agents, and PPCP pollutants are hard to remove by standard processes.

2. Dual-Defect S-Scheme Design

The team assembled Ti3C2 MXene quantum dots, sulfur-vacancy-rich MoS2 and oxygen-vacancy-rich CeO2 into a hierarchical S-scheme heterostructure, where directional charge transport forms across the Ce-O-Mo interface: electrons accumulate in the MoS2 conduction band for H2 evolution while holes in CeO2 drive pollutant oxidation.

3. Coupled Performance

The system couples efficient H2 evolution with degradation of trace PPCP pollutants, using organics to consume holes and promote electron utilization for hydrogen - a practical route that avoids sacrificial agents and precious metals.

Read the Chinese report: GEE: dual-defect S-scheme junction.