Symmetry Design of Metal–Organic Frameworks for High-Performance Piezocatalysis: Fundamental Mechanisms and Multi-Scale Structural Regulation

Driven by the pursuit of carbon-neutral and distributed energy systems, extensive efforts have been devoted to harvesting ubiquitous low-grade ambient mechanical energy. Piezocatalysis offers a unique light-independent and electricity-free pathway that converts mechanical vibration into reactive radical species. Conventional inorganic ferroelectrics and piezoelectric polymers face severe limitations originating from rigid lattice configurations, insufficient surface active sites, and unmodulable electronic band structures. Benefiting from reticular chemistry, metal-organic frameworks (MOFs) emerge as versatile piezoactive candidates. Crystallographic inversion symmetry, which acts as the core determinant of intrinsic lattice dipoles and strain-activated charge screening behavior, can be precisely regulated at the molecular level. Most existing reviews classify MOFs piezocatalysts primarily by metal-node types. However, a systematic analytical framework centered on symmetry breaking to clarify structure-activity relationships is still lacking. This review establishes a multi-scale symmetry modulation paradigm focusing on crystal inversion-symmetry engineering. It comprehensively demonstrates three fundamentally piezocatalytic mechanisms and systematically highlights the unique piezoelectric structural superiority of tunable MOFs over traditional piezoelectric materials. This work elaborates a three-tier symmetry engineering strategy covering intrinsic lattice regulation, metal-mediated dipole amplification, and multicomponent heterostructure construction. It summarizes full-scale bottlenecks involving fundamental mechanisms, material design, and device integration. This review delivers symmetry-oriented structural principles and theoretical support for the efficient utilization of low-grade mechanical energy. Finally, it discusses the prospects of artificial intelligence-assisted high-throughput screening to advance the rational exploration of high-performance, symmetry-compliant piezocatalytic MOFs.