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 kind 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 as high as 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.