Bifunctional bis(2-carboxyethyl)isocyanurate crystal for high-performance photocatalytic degradation of rose bengal dye and luminescence sensing of PO43−, NO3−, Cl−, Cr2O72− and F− ions

Abstract

A new crystal of bis(2-carboxyethyl)isocyanurate (KA@PS) was crystallized and employed to study its adsorption and photocatalytic properties. It displayed preferential adsorption of cationic dyes, methyl violet (MV), crystal violet (CV), rhodamine 6G (Rh6G) and methyl blue (MB) as well as anionic dyes, Congo red (CR), rose bengal (RB), and Eriochrome black T (EBT). Following that, the photocatalytic capability of KA@PS was investigated for easy degradation of all these dyes under UV-light irradiation. The dye adsorption activity can be related to charge transfer and the existence of a complex array of non-covalent contacts between them, whereas a 2.96 eV band gap has been employed for the photodegradation of dyes under UV-light irradiation. Furthermore, kinetic measurements show that both dye adsorption and photocatalytic degradation followed a pseudo-first-order process. The pH effects on colorant concentration in the presence of KA@PS in room illumination after 150 minutes for all organic dyes were also examined. It had high selectivity for the detection of PO₄³⁻, NO₃⁻, Cl⁻, Cr₂O₇²⁻ and F⁻ by fluorescence sensing. The quenching constants (K_sv) were 4.28 × 10⁴ M⁻¹, 8.06 × 10⁴ M⁻¹, 3.12 × 10⁴ M⁻¹, 2.69 × 10⁴ M⁻¹ and 3.93 × 10⁴ M⁻¹, respectively, with a detection limit (LOD) of 3.4 × 10⁻⁶ M (0.32 ppm) for PO₄³⁻, 6.1 × 10⁻⁶ M (0.38 ppm) for NO₃⁻, 3.3 × 10⁻⁶ M (0.12 ppm) for Cl⁻ ions, 1.96 × 10⁻⁶ M (0.58 ppm) for Cr₂O₇²⁻ and 4.3 × 10⁻⁶ M (0.08 ppm) for F⁻.