The regular octahedral CdS/K2Nb2O6 core-shell Z-Scheme heterojunction towards enhancing photocatalytic H2 evolution and degradation via synergism of carrier efficiency and light response.

The regular octahedral CdS/K 2 Nb 2 O 6 core-shell Z-Scheme heterojunction is synthesized via an approach of hydrothermal-chemical method. The CdS/K 2 Nb 2 O 6 nano-heterojunction (CdS/KNO-3) exhibits arresting enhanced photocatalytic HER (∼634.39 μmol g−1 h−1)/degradation (∼0.05428 min−1) than the monomer K 2 Nb 2 O 6 (∼27.8/14.4 folds) and CdS (∼20.3/10.0 folds), including a decent stability (average HER of ∼621.39 μmol∙g−1 h−1). It can be mainly attributed to the CdS/K 2 Nb 2 O 6 Z-Scheme heterojunction with appropriate potential gradient can promote the interface carrier driving to optimize carrier efficiency, including increasing carrier transport, extending carrier lifetime and reducing recombination. Additionally, the octahedral core-shell nanostructure can provide numerous active sites for decreasing overpotential and promoting electron diffusion, while improving the solar efficiency (high solar response of CdS), including shorting carrier pathway for photocorrosion optimization and increasing structural stability. [Display omitted] • Z-scheme heterojunction optimize carrier efficiency by greater Fermi levels gradient. • Core-shell structure can increase active sites to promote electron diffusion. • CdS nano-shell can enhance visible light response and shorten carrier pathway. • Regular octahedral nano-structure can increase structural stability. [ABSTRACT FROM AUTHOR]