NiFe-LDH/ZnCdS bimetallic hydroxide heterostructures for efficient multi-electron CO2 reduction

Efficient photocatalytic CO 2 reduction is limited by rapid carrier recombination and sluggish interfacial kinetics. Here, NiFe-LDH/ZnCdS (ZCS) heterostructures were fabricated by hydrothermal synthesis followed by electrostatic self-assembly. Mott–Schottky analysis, XPS, photoelectrochemical measurements, and density functional theory calculations collectively reveal staggered band alignment and interfacial charge redistribution, supporting a type-II charge-transfer pathway with improved carrier separation. The optimized 15NiFe-LDH/ZCS produced CO, CH 4 , C 2 H 4 , and C 2 H 6 at 16.54, 8.30, 1.22, and 4.70 μmol g −1 h −1 , respectively, while maintaining stable activity over 16 h. The enhancement originates from intimate interfacial contact, stronger visible-light harvesting, faster charge transport, and increased accessible active sites. These results establish a practical heterostructure-design strategy for multi-electron photocatalytic CO 2 conversion.