Phase-junction engineering steering Ru dispersion on ZnCdS for enhanced photocatalytic H2 evolution

Atomic-level control in crystal facet engineering offers a systematic approach to enhance catalytic performance by modulating microscopic properties such as electronic structure, surface energy, and coordination environment. Herein, we propose a phase-junction engineering strategy for ZnCdS (ZCS) solid solutions with atomic Ru loading to construct a high-performance catalyst (Ru/ZCS). The choice of sulfur source, thioacetamide (TA) versus thiourea (TR), plays a pivotal role in determining the crystal phase structure and photocatalytic performance. Microstructural characterizations reveal that ZCS-TA features intersecting (111) facets of ZnS and CdS, whereas ZCS-TR forms a homogeneous ZnCdS crystal phase. This structural distinction leads to the preferential anchoring of Ru single atoms at the phase junction of ZCS-TA, while Ru clusters form on ZCS-TR. Remarkably, Ru/ZCS-TA achieves an exceptional H 2 evolution rate of 30.3 mmol g −1 h −1 under visible light ( λ >420 nm), surpassing bare ZCS-TA by 12-fold and nearly doubling the performance of Ru/ZCS-TR. In-situ experiments and mechanistic studies attribute the superior performance of Ru/ZCS-TA to the optimized facet structure enabled by phase-junction engineering, which significantly enhances reaction kinetics. This work establishes phase-junction engineering as an innovative strategy for designing high-efficiency single-atom photocatalysts under mild conditions, providing promising potential for water splitting applications. The phase-junction engineering of ZnCdS (ZCS) crystal facets for atomic Ru dispersion enhances both activity and stability of photocatalytic H 2 evolution (PHE) via accelerating surface reaction kinetics and optimizing the reaction barrier. Download: Download high-res image (238KB) Download: Download full-size image