Multifunctional hydrophobic MOFs modified by rosin acid with oil–water separation and room temperature catalysis

Abstract

Metal-organic frameworks (MOFs) are high surface area porous materials with uniform pores. MOFs are among the widely investigated porous materials because of their potential applications in adsorption, oil–water separation, catalysis, and other such applications. However, MOFs are not stable enough in aqueous environments, which restricts their application in practice. We converted hydrophilic UiO-66-SH into hydrophobic UiO-66-RA by introducing rosin acid into organic linkers. The material was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The superhydrophobic UiO-66-RA was successfully constructed and the water droplet contacts angle reached 157.2°. Importantly, the obtained UiO-66-RA demonstrated stable oil–water separation performance, with separation efficiencies of up to 96.1% and 96.8% for both light and heavy oils. The separation efficiencies also reached more than 95.1% after five repetitions. For stable oil–water emulsions, UiO-66-RA also achieved effective separation. In addition, the catalyst Pd@UiO-66-RA was successfully prepared by hybridization of palladium chloride with UiO-66-RA. The catalytic yields of Pd@UiO-66-RA was 95.4%. And the yield could also be kept above 60% after five cycles of Sonogashira reaction catalyzed. This work offers a new type of superhydrophobic MOFs, the multifunctional MOFs has the potential for environmentally benign catalysis and purification of wastewater.