Synthesis of [Ta6O19] @MOF composite as a chloroacetaldehyde optical sensor in wastewater obtained from two waste-resourced precursors: Tantalum from capacitors and terephthalic acid from PET bottle

Abstract

Metal-organic frameworks (MOFs) can be derived from waste and used for various purposes to address environmental issues. MOFs possess superior adsorption and regeneration capabilities, making them effective for capturing various pollutants found in wastewater. Here, a rare Lindqvist polyoxometalate (POM), (Na8[Ta6O19]), was synthesized and used to fabricate a novel MOF-based composite (POTa@UiO-66) through a one-pot reaction with zirconium chloride (ZrCl4) and terephthalic acid (TPA). Some building blocks of the composite was then prepared using recycled materials obtained from capacitors and plastic bottles. According to FT-IR, SEM, UV–visible, and fluorescence analysis results, both composites showed structural similarity and exhibited efficient fluorescence detection properties for chloroacetaldehyde (CA) through the common aldehydes addition in aqueous media (at λex = 300 nm). A dynamic quenching process was suggested between the sensor and CA based on absorption spectra and Stern-Volmer plots. The low detection limits for both composites prepared by pure and recycled precursors were 5.3 × 10−8 M and 1.5 × 10−7 M, respectively.