Assembling phase-junctions based on metal-organic framework polymophism for enhanced overall CO₂ photoreduction activities

The conversion of solar energy into chemical fuels stands at the forefront of promising applications for metal-organic frameworks (MOFs), but the rapid recombination of photo-induced charge carriers within these frameworks poses a significant challenge to their photo-catalytic performance. Despite heterojunction construction has potential as a viable approach, its synthesis involves considerable complexity. Here, we present a distinct and well-defined phase junction based on polymorphic MOFs, achieved through an efficient one-pot synthesis process. This work not only paves the way for a robust platform for designing sophisticated MOFs complexes, but also illuminates the intricate hierarchical structure-function dynamics inherent in MOFs. The fabricated PCN-222-Ni@PCN-224-Ni (P@P) hybrid material exhibits extensive surface area, a porous matrix, and superior crystallinity. The harmonious alignment of the bandgap between PCN-222-Ni and PCN-224-Ni, establishing a phase junction for type-II carrier transfer, endows the resultant photocatalysts with exceptional visible-light-induced photoreduction capabilities for CO₂, along with augmented stability. This significant advancement represents a significant milestone in the applications of MOFs, especially in harnessing solar energy for the production of sustainable chemical fuels through the process of CO₂ photo-conversion.