Multivariate Hierarchies in Metal-Organic Frameworks

Hierarchy is one of the fundamental laws that governs nature, where ordered structures-from plant roots to human skin-optimize mass and energy flow through precisely hierarchical pores and chemical compositions. Mimicking this intricate design in artificial materials has remained elusive, as achieving simultaneous, precisely control over both pore architecture and chemical composition hierarchies within a single system posed great challenges. In this work, by developing a facile nanoemulsion-based post-synthetic strategy, we break this barrier and achieve multivariate hierarchies in metal-organic frameworks (MOF) single crystal, enabling the first creation of MOF with simultaneously sequentially ordered hierarchical pores (micropores→mesopores→macropores) and hierarchical chemical compositions (distinct functional layers). This true biomimicry showcase promoted charge transfer efficiency and accelerated reaction kinetics which are similar to the natural systems. In addition, novel multivariate hierarchies like "multi-element hierarchical pores" for multifunctionality and "cross-linked hierarchical pores" for pore structural hybridization can be also created, transcending traditional material limits. By mirroring nature's hierarchical genius at the nano world, this work establishes a paradigm for the next-generation bio-inspired materials with life-like efficiency and complexity.