Tunning heterostructures interface of Cu2O@HKUST-1 for enhanced photocatalytic degradation of tetracycline hydrochloride

Cu 2 O is an attractive material for the architectural design of integrated nanomaterials in photocatalysis. Herein, a contrastive study was carried out to explore the influence of morphology/exposed Cu 2 O facets on the template growth process and the difference of fabricated composites in photocatalysis performance. A series of Cu 2 O@HKUST-1 with core–shell structure was developed via a self-confinement strategy, in which Cu 2 O nanocrystals with various shapes (cube, truncated octahedron and octahedron) act as self-confinement template to grow Cu-based metal–organic frameworks (HKUST-1) shell. It was revealed that the growth of HKUST-1 on Cu 2 O crystal depended on the original Cu 2 O crystal. The exposure of (1   1   1) facet in Cu 2 O was more favorable to the growth of HKUST-1 than (1   0   0) crystal plane. Optical and photoelectrochemical characterizations revealed that the cubic Cu 2 O@HKUST-1 exhibited the outstanding light response and most efficient interfacial charge transfer and separation among three types of composites. As a result, the degradation rates of tetracycline hydrochloride (TC-HCl) by cubic Cu 2 O@HKUST-1 under the visible light irradiation was 95.35% within 60 min, which was much higher than truncated octahedral Cu 2 O@HKUST-1 (78.81%) and octahedral Cu 2 O@HKUST-1 (66.58%). Mechanism explorations including radical capture experiments, electron paramagnetic resonance and band structure analysis showed that type II heterojunction was formed in cubic Cu 2 O@HKUST-1 and truncated octahedral Cu 2 O@HKUST-1, which was conducive to the separation and transfer of photo-generated carriers. However, type I heterojunction existed in octahedral Cu 2 O@HKUST-1 lead to the recombination of photocarriers. These findings revealed the interface-dependent photocatalytic performance in Cu 2 O@HKUST-1 and provided useful guidance for controllable construction of photocatalysts with heterojunction structure.