Facile construction of tourmaline@MOFs composites via micron-scale electrical polarization to enhance photodegradation of gaseous formaldehyde

The functional composition approach for promoting metal-organic framework (MOF)-based photo-catalysis has usually been hampered by grain incompatibility, resulting in an insufficient contact interface. Herein, spontaneously polarized tourmaline (TM) was proposed to be combined with MOFs to generate a polarization-induced electric field on a micron-scale, which could improve HCHO photocatalytic degradation performance. Based on the micron-scale electrical polarization strategy, facile micron-interface construction in TM-ZrO2@NU66 (NH2-UiO-66, UiO = University of Oslo) and TM-TiO2@NM125 (NH2-MIL-125, MIL = Materials Institute Lavoisier) dramatically improved the remnant polarization (2.8 and 2.4 times), charge transfer rate (3.8 and 5.9 times), and center dot OH/center dot O-2(-)/h(+) formation. Consequently, two TM@MOFs exhibited 6-90 times higher formaldehyde removal rates than previously reported state-of-the-art photocatalysts. The fabricated composites exhibited a high mineralization rate, deep formaldehyde removal (>80 % of total organic carbon (TOC) removal within 150 min), and outstanding recycling stability. This study narrates an innovative and straightforward method for creating composites based on MOFs, significantly reducing the challenges associated with ensuring MOF compatibility with other functional materials.