Fe-metal organic framework converts mechanical energy with piezoelectric polarization to remove carbamazepine in water: Efficiency, pathway and mechanism

Piezocatalysis is a new technique that directly transforms mechanical energy into chemical energy. Although this approach can potentially be used to replace traditional water treatment methods, the structural tailorability and limited surface area of conventional inorganic piezoelectric materials restrict their catalytic efficiency. Herein, we employed a piezoelectric material made of an organic Fe-metal organic framework (MOFs) to purify water via piezocatalysis. We analyzed the physicochemical properties of MIL-100(Fe), including its piezoelectricity, bandgap structure, and charge separation efficiency. Carbamazepine (CBZ) was used as a representative aqueous drug pollutant, and MIL-100(Fe) removed 92 % of CBZ in 30 min via applying ultrasonication (US), which was 5.1 and 11.5 times higher than either the individual MIL-100(Fe) or US. The mechanical US stresses generated a built-in electric field in MIL-100(Fe) to promoted free charge migration, and also modulated the band structure of the sample. This promoted the production of reactive oxygen species. In this work, shows that porous piezoelectric nanostructures based on MOFs can convert mechanical energy into chemical energy to drive chemical oxidation processes.