Removal of organic pollutants in water by the MCM-41 anchored with nickel(II) and copper(II) complexes

Abstract

In photo catalysis, the transition metals are an emerging class of materials due to their activity and stability with ligands coordination. Such metal can be stabilized by the Schiff base ligands, preventing the leaching of the metal active centers during the catalytic process The present works describe the copper(II) and nickel(II) Schiff base complexes bearing hydroxyquinoline moiety that were synthesized, directly grafted onto amino linked MCM-41 materials. The synthesized materials (SQA, NSQA & CSQA) photocatalytic ability examined in the photooxidation of toxic organic pollutants such as fluorescein (FLU), crystal violet (CV), parathion methyl (PM), and 2,4,6-trichlorophenol (TCP). The stability and activity due to metal to ligand charge transfer may have a prominent role in the degradation of exodus toxins. The photooxidative characteristics of fluorescein, crystal violet, parathion methyl, and trichlorophenol are studied under UV light irradiation, and all show the Pseudo-first order kinetics in the presence of NSQA and CSQA hybrid catalysts. The hybrid composites CSQA, NSQA has good activity when compared with those of MCM-41 and SQA. Albeit, this phenomenon also depends on the LMCT and redox properties of the metals and electron-rich species of the porous matter. The NSQA and CSQA have more degradation performance when compared to porous silica and SQA. In the photocatalysis, the crystal violet removal percentages are 17%, 27%, 93% and 100% and 9%, 13%, 75% and 100% in case of fluorescein for the MCM-41, SQA, NSQA and CSQA respectively. The parathion methyl removal efficiency has 91%, 100%, 51% and 35%, whereas the removal percentage for the 2,4,6-trichlorophenol are 41%, 34%, 81% and 100% for MCM-41, SQA, NSQA and CSQA respectively. these model dyes are well fitted with Pseudo-first order kinetic models. Hence, the copper hybrids have 100% ability in the eco-friendly destruction of model organic pollutants. The photocatalysts reusability and stability were checked with the fresh catalysts.