A multi-interface CdLa2S4/Mn0.5Cd0.5S-CoxP heterostructure integrating S-scheme and Schottky junctions for enhanced photocatalytic hydrogen evolution

The development of efficient and durable non-noble metal photocatalysts remains a major challenge, primarily owing to the fast recombination of photogenerated charge carriers and sluggish interfacial reaction kinetics. In this work, a ternary composite photocatalytic system, CdLa 2 S 4 /Mn 0.5 Cd 0.5 S-Co x P (CdLa 2 S 4 /MCS-Co x P), was rationally designed and constructed by coupling the S-scheme heterojunction with the metal-semiconductor Schottky interface, aiming to synergistically enhance multi-channel charge separation and migration. The construction of an S-scheme heterojunction comprising CdLa 2 S 4 and Mn 0.5 Cd 0.5 S (MCS) significantly facilitates the spatial separation of photogenerated electrons and holes driven by the built-in electric field, while simultaneously preserving their strong redox capability. Meanwhile, the Co x P acts as both an efficient electron acceptor and proton reduction site, its Schottky barrier at the interface further lowers the energy barrier for the hydrogen evolution reaction and accelerates surface reaction kinetics. Consequently, the CdLa 2 S 4 /MCS-Co x P composite exhibits a remarkable hydrogen evolution rate of 11.04 mmol g −1 h −1 , outperforming pristine MCS and CdLa 2 S 4 by factors of 10.32 and 38.07, respectively. This study offers a practical strategy for the rational design of multi-interface photocatalytic architectures with robust redox ability.