Facile construction of noble-metal-free Mn0.3Cd0.7S heterophase junction enriched with sulfur vacancies for efficient seawater splitting

Constructing heterophase junctions is an efficient strategy to address lattice mismatch in semiconductors and enhance the separation efficiency of photogenerated charge carriers. Herein, a facile approach is reported to fabricate sulfur-vacancy-rich MCS-T (Mn 0.3 Cd 0.7 S heterophase junction) by regulating the solvent composition during solvothermal synthesis. The charge carrier separation and transport kinetics at MCS-T are systematically unraveled by combining spectroscopic characterizations, electrochemical measurements and density functional theory (DFT) calculations. Under visible-light irradiation, MCS-T achieves a hydrogen evolution rate of 18.66 ± 0.27 mmol·g −1 ·h −1 in simulated seawater, which is 2.3 and 5.8 times higher than those of MCS-ZB (cubic-phase Mn 0.3 Cd 0.7 S) and MCS-WZ (hexagonal-phase Mn 0.3 Cd 0.7 S), respectively. Furthermore, the as-prepared catalyst exhibits excellent corrosion resistance, with no obvious degradation in hydrogen evolution activity observed after a 20 h cyclic stability test. This work highlights the great potential of metal sulfide heterophase junctions in photocatalytic applications and provides a rational guideline for realizing efficient charge transfer and enhanced photocatalytic performance. Download: Download high-res image (113KB) Download: Download full-size image