Construction of a novel metal–organic framework adenine-UiO-66 piezocatalyst for efficient diclofenac removal

Piezoelectric materials, which could collect and convert mechanical energy into electrical energy, have recently emerged as promising catalysts for pollutants removal sustainably. Unfortunately, it remains a challenge to enhance the intrinsic piezoelectric property of piezoelectric materials. Herein, for the first time, the polar molecule adenine was introduced as a linking agent in the synthesis process of Zr-based UiO-66 (denoted as AD-U) to enhance the structure asymmetry and piezoelectric properties of UiO-66. The piezoresponse force microscopy (PFM) and ferroelectric hysteresis loop demonstrated that AD-U catalyst exhibited significantly enhanced piezoelectric potential than UiO-66. Furthermore, a series of electrochemical characterization evidenced that AD-U displayed higher charge separation efficiency than UiO-66. As expect, the optimized AD-U shown promoted diclofenac sodium (DCF) piezoelectric degradation efficiency by harvesting stirring energy compared with pure UiO-66. The electron paramagnetic resonance (EPR) spectra and trapping agent experiments convinced that h+ play the major role for destroying the DCF molecules. Moreover, three possible degradation pathways of DCF were put forward by DFT and liquid chromatography mass system (LC-MS). Our work offers a new pathway to enhance piezoelectric property of MOFs and extend the application of MOFs in the field of piezocatalysis.