β-Phosphonated Glycine Pendant Groups Grafted on Styrene-6.7% Divinylbenzene Copolymers: Synthesis and Their Application as Photocatalysts

Abstract

Environmental pollution from organic contaminants caused by textile dyeing is a real danger. Wastewater from the textile industry has high organic loads, as well as dyes and chemical compounds used in their preparation. Among the azo dyes, Congo red (CR) dye is widely used as a model in the experimental studies of textile wastewater treatment. Heterogeneous photocatalysis consists of UV or VIS light irradiation of various types of organic compounds in water in the presence of a solid catalyst; it is considered an important technique for the purification and reuse of aqueous effluents. In the present study, two novel compounds of β-phosphonate-type glycine pendant groups grafted on S-DVB copolymer were used for the decontamination of Congo red dye polluted water. They were characterized by FTIR spectroscopy, scanning electron microscopy, EDX spectroscopy, thermogravimetric analysis and UV-VIS spectroscopy. By using 25 mg/L initial concentration of Congo red dye and a catalyst concentration of 1 g/L and 240 min of irradiation, a photocatalysis efficiency of 98.6% in the case of [(diethyl)(phosphono)methylene]glycine pendant groups grafted on styrene-6.7% divinylbenzene copolymer (EthylAmAcid material), and of 83.1% in the case of [(dibenzyl)(phosphono)methylene]glycine pendant groups grafted on styrene-6.7% divinylbenzene copolymer (BenzylAmAcid material), respectively, was achieved.