Synthesis of immobilized ZnO over polyurethane and photocatalytic activity evaluation for the degradation of azo dye under UV and solar light irardiation

Abstract

Zinc oxide (ZnO) nanoparticles were immobilized on polyurethane foam (PUF) and employed for the degradation of Acid black 1 dye (AB1). The ZnO/PUF was characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray (EDX) techniques. Process variables i.e., dye concentration, pH, concentration of H _2 O _2 , irradiation time were optimized for maximum degradation of dye. ZnO/PUF showed promising efficiency for the degradation of AB1 dye and up to 86% and 65% dye degradation was achieved under UV and solar light irradiation at neutral pH, 4% H _2 O _2 , 240 min/sunlight and 75 min/UV irradiation time using 40 mg l ^−1 dye initial concentration. The optimum conditions were applied for the treatment of textile wastewater and biological oxygen demand (BOD) and total organic carbon (TOC) were reduced up to 70% and 80%, respectively. In view of promising photocatalytic activity (PCA), ZnO/PUF could possibly be used for the treatment of wastewater contains dyes.

Keywords

• immobilization
• ZnO
• photocatalysis
• acid black 1
• optimization