Water-Etched Approach to Hierarchically Porous Metal-Organic Frameworks with High Stability

The development of hierarchically porous metal-organicframeworks(MOFs) with high stability is desirable to expand their applicationsbut remains challenging. Herein, an anionic sodalite-type microporousMOF (Yb-TTCA; TTCA(3-) = triphenylene-2,6,10-tricarboxylate)was synthesized, which shows outstanding catalytic activities forthe cycloaddition of CO2 into cyclic carbonates. Moreover,the microporous Yb-TTCA can be transformed into a hierarchicalmicro- and mesoporous Yb-TTCA by water treatment withthe mesopore sizes of 2 to 12 nm. The hierarchically porous Yb-TTCA (HP-Yb-TTCA) not only exhibits a highthermal stability up to 500 & DEG;C but also shows a high chemicalstability in aqueous solutions with pH values ranging from 2 to 12.In addition, the HP-Yb-TTCA displays enhanced performancefor the removal of organic dyes in comparison with microporous Yb-TTCA. This work provides a facile way to construct hierarchicallyporous MOF materials. Ananionic sodalite-type microporous metal-organicframework (MOF) was successfully transformed into a hierarchical micro-and mesoporous MOF by water treatment with the mesopore sizes of 2to 12 nm. This hierarchically porous MOF not only exhibits high thermaland chemical stabilities but also shows enhanced performance for theremoval of organic dyes in comparison with microporous MOF.