Photo-catalytic dye degradation of methylene blue by using ZrO2/MWCNT nanocomposites

Abstract

Photocatalytic degradation of the dyes was deliberated by altering the catalyst and dye concentrations. The Zirconium oxide/multiwall carbon nanotube (ZrO2/MWCNT) catalyst was facilely synthesized by a hydrothermal synthesis method. The nanocomposite ZrO2/MWCNT was formed in hydrothermal condition 95 °C of low growth temperature. The physico-chemical properties were successfully characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), dynamic light scattering (DLS) analysis, and X-ray photoelectron spectroscopy (XPS). The presence of Orbicular shaped ZrO2 nanocrystallines and multiwall carbon nanotubes was characterized by XRD pattern, and shows the presence of ZrO2 and MWCNT with the 2θ peaks at 19.62, 22.5 & 30.2. The thermal behavior of the ZrO2/MWCNT partials was also investigated by differential thermal analysis, and their vibrational bands were identified by infrared spectroscopy. The photo catalytic degradation of methylene blue in industrial wastewater was observed under UV light irradiation using the synthesized ZrO2/MWCNT as catalyst. The results revealed that the ZrO2/MWCNT nanoparticles exhibited high degeneration with COD and TOC reducing from 241 mg/L and 148.00 mg/L to 2.34 mg/L and 1.26 mg/L respectively with an efficiency of 90–94% over 25–60 min duration of UV irradiation. In comparison with the pristine Zirconium oxide and MWCNT, the composite ZrO2/MWCNT nanoparticles exhibited more efficient, durable and stable photo-catalytic activity during experiments. HIGHLIGHTS The ZrO2/MWCNT nanoparticles exhibited high degeneration efficiencies (90–94%) for 25–60 min of UV irradiation time.; The ZrO2/MWCNT nanocomposite exhibits a highly structural uniqueness combined with hydrothermal method and has an large surface area.; The present investigation serves as a base-line data for future studies on ZrO2/MWCNT nanocomposites for wastewater treatment.;

Keywords

• methylene blue
• multiwall carbon nanotube (mwcnt)
• photocatalytic activity
• zirconium oxide