Preparation and structural investigations of the composite containing lead oxide and graphite as reinforcements and its adsorptive and photocatalytic dye-degradation activity

Abstract

Water contamination by lead (Pb+2) has attracted enormous research owing to its potential carcinogenic, mutagenic, and toxic effects. Composite membranes are highly efficient, and cost-effective adsorbents for the elimination of heavy metals from water. The present study involves the preparation, characterization, and adsorption properties of a novel (Polyvinyl chloride) PVC/PbO-graphite adsorptive composite membrane (ACM) for the effective removal of Pb+2 ions from water. Four composite membranes were fabricated using PbO-graphite as a filler (5, 10, 15, and 20 %) and PVC as a binder. The physiochemical properties such as water uptake, swelling degree, density, and porosity of the composite membrane were studied. All the mentioned properties were decreased and the adsorptive capacity of the membranes (5.54–9.01 mg/g) declined with increasing filler percentage. It was observed that an increase in the initial concentration, adsorption, time, and pH improved the removal efficiency of the membranes. Maximum adsorption was observed for 5 % filler composite at 80 ppm initial concentration of Pb+2 in 300 min time at a pH of 6. Furthermore, both Langmuir and Freundlich adsorption isotherms were applied to investigate and understand the adsorption ability of the prepared ACMs. These isotherms well explained the adsorption process with an average R2 of 0.9860 and 0.9813 respectively. But the results were best aligned with the Langmuir adsorption mechanism (average R2 = 0.9860). The ACMs were also utilized for the photodegradation of Congo red dye and the ACMs (20 %) degraded about 71 % dye within 50 min.