Remediation of Methylene Blue Dye from Wastewater by Using Zinc Oxide Nanoparticles Loaded on Nanoclay

Dyes are one of the major environmental pollutants throughout the world, leading to pollution and numerous diseases. Though several techniques have been applied for the remediation of dyes, most of them are ineffective. The authors developed a halloysite clay/zinc oxide nanocomposite (HC/ZnONC) via a chemical route in the present study. The nanocomposite and its constituents, i.e., raw halloysite clay (HC) and zinc oxide nanoparticles (ZnONPs) (synthesized using the same chemical method) were analyzed for their detailed properties by sophisticated instruments. The field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) analysis showed spherical-shaped ZnONPs with an average size of 54.9 nm and tube-like shapes of HC with a diameter ranging from 40-200 nm and a length at the micron scale, while the nanocomposite had incorporated ZnONPs in their tube-like structures. Ultraviolet-Diffuse Reflectance Spectroscopic (UV-DRS) study revealed the photocatalytic ability of the nanocomposite with a band of 3.08 eV. A high surface area of 60.25 m(2)/g and the microporous and mesoporous nature of the nanocomposite were confirmed by the Brunauer-Emmet-Teller (BET) surface area analyzer. Finally, the developed nanocomposite was used for the remediation of methylene blue from the aqueous solutions, and the efficiency of removal varied from 90 to 97%.

Automated summary

The authors developed a halloysite clay/zinc oxide nanocomposite with photocatalytic activity and high surface area, and demonstrated its efficient removal of methylene blue from aqueous solutions.