A multipurpose organometallic pyridyl Schiff base-modified poly(divinylbenzene) matrix for the catalytic removal of nitrophenols and polycyclic pollutants

Abstract

Widespread organic pollutants in wastewater include toxic nitrophenols and polycyclic molecules. Here, we aim to develop a single multipurpose catalyst capable of degrading these structurally dissimilar contaminants by preparing a pyridyl Schiff base-functionalized poly(divinylbenzene) porous organic polymer displaying Ag complexes (PDVB-PA@Ag). PDVB-PA@Ag hydrogenated 4-nitrophenol (4-NP) efficiently to valuable and less toxic 4-aminophenol with an optimized reaction rate of 45.4 × 10−3 s−1 and apparent activation energy of only 20.1 kJ mol−1. The same catalyst also readily hydrogenated the isomers of 4-NP as well as nitrophenols with several nitro groups and halogenated nitrophenols with reaction rates ranging from 4.0 to 20.3 × 10−3 s−1. In addition, the multiuse PDVB-PA@Ag was capable of carrying out a second type of reaction and degraded multiple polycyclic dyes commonly found in wastewater including auramine O, basic blue 17, aniline blue, and malachite green through Fenton-like oxidation. PDVB-PA@Ag-based degradation processes for the four toxic dyes evaluated were efficient with pseudo-first order reaction rates varying between 1.2 × 10−2 to 3.7 × 10−2 min−1. By coordinating an array of versatile catalytic complexes on an extensive and stable porous support, PDVB-PA@Ag was made highly performant at completing different essential water-cleaning processes.