Tailoring the structure and function of metal organic framework by chemical etching for diverse applications

Rational structure and function modification of metal organic frameworks (MOFs) would enable them with desirable properties. In this regard, MOF modification by chemical etching has been extensively studied, aiming to regulate the pore structure, reshape MOF surface, construct complex structure, manipulate defects, introduce heteroatoms and realize the self-templated conversion to layered metal hydroxides (LDHs). Distinctively, the resultant etched MOFs and etched MOF-based materials have displayed distinctive properties associated with better performance in diverse applications as compared to pristine MOFs. Given the advantages of etching over other technologies, a review focusing on the topic of “etching MOFs” is highly required. Here, the strategies to modify MOFs by chemical etching are broadly classified into four categories including pore engineering, surface/facet modification, defect modification and self-templated conversion to LDHs. In particular, the mechanism and key parameters of each etching strategy on various MOFs are fully discussed, followed by the utilization of etched MOFs and etched MOF-derived materials in diverse applications. Finally, current challenges and research directions for the further development of etching MOFs are proposed.