Cu-containing polyoxometalate-based melamine in the environmental remediation of toxic organic pollutants

Abstract

Harmful industrial pollutants are the most important and substantial challenges in ecological and environmental processes. Therefore, environmental remediation of these types of toxic materials is an important issue. The main purpose of the present study is the catalytic reduction of some organic dyes and nitro aromatic compounds as toxic contaminants in the presence of polyoxometalates (POMs). At first, the transition metal-substituted Keggin-type POM-based melamine was prepared and identified using different techniques such as FTIR, XRD, TGA, and FE-SEM. Then, the catalytic performance of these synthesized compounds in the reduction of some nitro aromatic compounds and organic dyes was investigated. By copper-substituted Keggin-type POM-based melamine (CuPOM@melamine), the best result was obtained with higher conversion and shorter reaction time. All reactions were carried out using NaBH₄ as the reducing reagent at room temperature and in water as solvent. Furthermore, the apparent rate constants were determined by considering pseudo first-order kinetic studies for these reactions. The main purpose of the present study is introducing an impressive way to eliminate hazardous industrial pollutants using POM-based melamine. The choice of melamine as a support for increasing the surface area, electron transfer ability and catalytic activity is another important aspect of this purpose. This effective system was used in water as the solvent and at room temperature. Easy preparation, nontoxicity, simple to operate, low-cost, environmentally friendly, and efficient catalytic activities are priorities of this system that could be applied in the environmental processes.