Synthesis of an efficient MOF catalyst for the degradation of OPDs using TPA derived from PET waste bottles

Abstract

In this study, a method for degrading PET-waste plastic bottles using ZnCl2:Urea as a catalyst was developed, resulting in high conversion (87%). The terephthalic acid obtained from the degradation of Waste PET Bottles (WPTs) was combined with copper and zinc salts to synthesize bimetallic metal–organic frameworks (MOF). The effectiveness of a bimetallic Cu-Zn(BDC)-MOF in catalyzing the reduction reaction of organic pollutant dyes (OPDs) was investigated, and the degradation efficiency of individual dyes was optimized, achieving over 95% degradation within 6–12 min under optimal conditions. Various techniques, including FT-IR, XRD, FE-SEM, EDS, and TEM were used to characterize the synthesized MOF. Results showed that the catalytic activity of Cu-Zn-MOF in reduction reaction of OPDs was enhanced by increasing the copper content. The reaction kinetics were investigated following pseudo-first-order kinetics with rate constants of 0.581, 0.43, 0.37, and 0.30 min−1 for Methylene Blue (MB), Methyl Orange (MO), 4-Nitrophenol (4-NP), and 4-Nitroaniline (4-NA), respectively. The investigations revealed that the produced catalyst exhibited excellent stability and recoverability, while its activity remained well-preserved even after undergoing three reuse cycles.

Sustainable conversion of polyethylene plastic bottles into terephthalic acid, synthesis of coated MIL-101 metal–organic framework and catalytic degradation of pollutant dyes

“…While a comprehensive investigation into the degradation mechanism remains outstanding, existing literature posits a potential mechanism for the reduction of COPs (MB and 4-NP), illustrated in Fig. 9 39 , 66 , 67 . Studies suggest that the incorporation of doped silver metal sites onto the MIL-101 framework initiates a reduction in energy band gaps, thereby narrowing the energy level gap between the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) levels.…”

“…In recent years, MOFs have been extensively studied in environmental chemistry 37 – 39 . These MOFs, composed of organic linkers like terephthalic acid (TPA) and various metal active sites (gold, iron, zinc, copper, silver, etc.…”