Hydrothermal synthesis of lead dioxide/multiwall carbon nanotube nanocomposite and its application in removal of some organic water pollutants

Abstract

Lead dioxide/multiwall carbon nanotube (PbO₂/MWCNT) nanocomposite was synthesized by hydrothermal formation of lead dioxide on functionalized MWCNT. PbO₂ nanoparticles were formed from 0.015 M Pb(OH)₃⁻ (75 ml) solution in the presence of polyvinyl pyrrolidone (0.1 g). The solution was mixed with ammonium persulfate (NH₄)₂S₂O₈ as oxidizing agent and transferred to 100 ml Teflon-lined stainless steel autoclave heating it to 60 °C for 3 h. To prepare nanocomposite, PbO₂ formation was carried out in the presence of ultrasonically dispersed MWCNT. A black-brown product was formed in reaction vessel. The product was collected and then dried in an oven at 70 °C for 24 h. The morphology and composition of precipitate were investigated by X-ray power diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy and transmission electron microscopy (TEM). The results of XRD and TEM show globular α-PbO₂ nanoparticles immobilize on the surface of the MWCNTs. Also, TGA results demonstrated the presence of CNT in nanocomposite. The prepared PbO₂/MWCNT nanocomposite is used to construct the solid-phase cartridge. The performance of solid phase in the removal of pesticides from drinking water is determined by gas chromatography–mass spectroscopy (GC–MS) analysis. The average adsorption depends on concentration of spiked pollutants and their relative standard deviations were between 1.4 and 11 %.