Hierarchical hollow UiO-66-NH2/CdS heterostructure with synergistic mass transport and charge separation for enhanced photocatalytic hydrogen production

Abstract

Metal–organic frameworks (MOFs) with tunable structures and high surface areas have emerged as a class of promising candidates for photocatalytic applications. However, their photocatalytic efficiency is limited by high interfacial charge transfer resistance and rapid electron–hole recombination. Herein, we present the preparation of hollow UiO-66-NH₂ with wrinkled surfaces (H-UiO-66-NH₂) to enhance mass transport while simultaneously reducing electron migration distances. Moreover, the as-prepared hollow UiO-66-NH₂ is then deposited with CdS to facilitate the charge separation and transfer. These synergistic effects collectively optimize the photocatalytic performance of MOF-based composites. The optimized H-UiO-66-NH₂/CdS composite exhibits a hydrogen evolution rate of 3596.48 μmol g⁻¹ h⁻¹ under UV-visible light illumination, which is 134 times and 59.3 times higher than that of pristine hollow H-UiO-66-NH₂ and the solid UiO-66-NH₂/CdS composite with a smooth surface. This work highlights the potential of morphology-engineered MOF heterostructures for advanced photocatalytic applications.