Tailoring the Architecture of Metal-Organic Frameworks: Precision Etching for Engineered Defects and Surfaces

Metal-organic frameworks (MOFs) have emerged as promising materials owing to their high surface areas, tunable pore sizes, and diverse functionalities. However, their practical deployment is frequently hindered by intrinsic microporosity and structural fragility. In this review, we systematically analyze recent advancements in MOF etching techniques, which strategically modify framework architectures to enhance mass transport, expose active sites, and improve stability. The discussion encompasses a range of methods—including acid, base, ion, solvent, vapor, selective, in-situ, pyrolysis, and physical etching—with emphasis on the underlying mechanisms that govern the formation of hierarchical pore structures, defect engineering, and heterojunction formation. Notably, etching approaches facilitate precise control over crystal morphology and surface chemistry, thereby optimizing MOF performance in catalysis, electrocatalysis, photocatalysis, adsorption, energy storage, sensing, and biomedical applications. We also outline challenges such as etchant toxicity, over-etching risks, and scalability, while highlighting emerging strategies and computational simulations to refine the etching process. Ultimately, this review underscores the transformative impact of etching on MOF properties, paving the way for the design of next-generation multifunctional materials that address critical issues in environmental remediation, energy conversion, and beyond.