Popcorn-like ZnCdS-based nanospheres with hierarchical tandem heterojunctions synergy for efficient photocatalytic performance.

[Display omitted] • Unique popcorn-like nanosphere structure endows abundant active sites. • DFT theoretical calculation reveal the transfer pathway of charges. • Hierarchical tandem heterojunctions promote the separation of carriers. • The H 2 production efficiency is 50 times higher than the unmodified material. • It offers a new method for green energy conversion and hydrogen energy separation. Heterojunction engineering is widely recognized as one of the most effective strategies for enhancing photocatalytic performance and suppressing photocorrosion by promoting efficient carrier separation and transfer. In this work, popcorn-like ZnCdS-MoS 2 @Co 3 O 4 nanospheres with large specific surface areas and hierarchical tandem heterojunctions were synthesized via one-pot in-situ self-assembly combined with hole-driven photodeposition. Based on the highly uniform dispersion of MoS 2 as an electron collector in the system and precise deposition of Co 3 O 4 as a photogenerated hole collector driven by photogenerated carriers at the hole enrichment position, it can efficiently catalyze the photocatalytic hydrogen evolution in water. Compared to ZnCdS, the optimized ZCS-M@0.5C exhibits a 50-fold increase in visible-light-driven hydrogen evolution efficiency, achieving 18.73 mmol·h−1·g−1 and maintaining stability after a 20-hour cycle test. Additionally, the apparent quantum yield reaches a remarkable 10.11% at 420 nm. Experimental characterization tests and differential charge density analysis have confirmed the efficient ability of Pt-like MoS 2 to induce electron separation and transportation, while p-type semiconductor Co 3 O 4 accumulates holes through the p-n junction. Both theoretical and experimental evidence show that the incorporation of dual-internal electric fields facilitates bi-directional charge separation and rapid transfer. The photocatalytic performance is improved through a synergistic effect involving hierarchical tandem heterojunctions. This work presents a novel approach to fabricating highly efficient photocatalysts with multi-heterojunctions through synergistic effects. [ABSTRACT FROM AUTHOR]