Covalently bonded interfaces with delocalized π electrons in a MOF-in-MOF heterojunction for efficient gas–solid phase CO2 photoreduction

The interfaces in heterostructure photocatalysts play an important role in charge migration, but the rational controllable interfacial construction remains a challenge. Herein, a covalently bonded interface with delocalized π bonds was controllably constructed via the encapsulation of UiO-66-NH2 nanoparticles in MUV-10 skeletons. The UiO-66-NH2/MUV-10 heterojunction enabled both efficient capture and conversion of CO2 and H2O. The delocalized π bond in the covalent interface efficiently accelerated interfacial charge migration, suppressed carrier recombination, and reduced the work function for electronic effusion. As a consequence, UiO-66-NH2/MUV-10 exhibited superior CO2 photoreduction activity with H2O under visible light irradiation in the gas–solid phase. The CO evolution rate reached as high as 38.7 μmol g−1 h−1, which surpassed that of most commonly reported gas–solid phase photocatalysts. This work not only provides a feasible strategy for the controllable construction of interfaces but also demonstrates the great potential of interfacial engineering for efficient photocatalysis and other related areas.