Synergistic lattice-strain and phase engineering of CdS-O/1 T/2H-MoS2 for enhanced photocatalytic hydrogen evolution

Synergistic strain/phase engineering boosts photocatalytic hydrogen evolution performance. • The CdS-O/MS-5 achieves a high hydrogen evolution rate of 68.71 mmol·g −1 ·h −1 and AQE of 48.49%. • Strain-enhanced charge transfer couples with metallic/semiconducting phase junctions. While high-efficiency photocatalytic water splitting is pivotal for a sustainable hydrogen economy, its widespread implementation is hindered by sluggish charge-carrier kinetics and the formidable overpotentials inherent to traditional semiconductor. Here, we report a dual-optimization strategy to transcend these limitations by integrating oxygen-doped CdS (O-CdS) with a 1 T/2H-MoS 2 phase-engineered co-catalyst. The interstitial incorporation of oxygen induces a pronounced lattice expansion within the CdS framework, which reconfigures the electronic band structure by introducing additional electronic states near the Fermi level. These emergent states act as energetic stepping stones, facilitating efficient charge injection into the co-catalyst. Concurrently, the rational design of the 1 T/2H-MoS 2 metallic/semiconducting homojunction facilitates efficient interfacial charge extraction and provides abundant active sites for proton reduction. This synergistic integration of lattice-strain engineering and phase-controlled co-catalytic architectures simultaneously elevates photocatalytic activity and long-term durability. The optimized system exhibits a 2.5-fold enhancement in hydrogen evolution performance (68.71 mmol g −1 h −1 ) over the pristine CdS. Our findings establish a robust paradigm for leveraging lattice distortion and polymorphic phase engineering to optimize solar-to-chemical energy conversion in hybrid semiconductor architectures.