Photocatalysis and adsorption kinetics of azo dyes by nanoparticles of nickel oxide and copper oxide and their nanocomposite in an aqueous medium

PeerJ

article

Hajra Ahsan¹  Muhammad Shahid²  Muhammad Imran³  Faisal Mahmood¹  Muhammad Hussnain Siddique²  Hayssam M. Ali⁴  Muhammad B.K. Niazi⁵  Sabir Hussain¹  Muhammad Shahbaz⁶  Mudassar Ayyub¹  Tanvir Shahzad¹ 

[1] Department of Environmental Sciences, Government College University, Faisalabad;Department of Bioinformatics and Biotechnology, Government College University, Faisalabad;Department of Environmental Sciences, COMSATS University Islamabad, Vehari-Campus;Botany and Microbiology Department, College of Science, King Saud University;School of Chemical and Materials Engineering, National University of Sciences & Technology;Centre for Environmental and Climate Science, Lund University

关键词: Metal oxides nanocomposite;    Photocatalysis;    Adsorption;    Azo dyes degradation;    Freundlich model;    Langmuir model;    Pseudo-second order kinetic model;   

DOI  :  10.7717/peerj.14358

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundAzo dyes are recalcitrant organic pollutants present in textile industry effluents. Conventional treatment methods to remove them come with a range of disadvantages. Nanoparticles and their nanocomposites offer more efficient, less expensive and easy to handle wastewater treatment alternative.MethodsIn this study, nanoparticles of nickel oxide (NiO-NPs), copper oxide (CuO-NPs) and their nanocomposite (NiO/CuO-NC) were synthesized using co-precipitation method. The functional groups present on the surface of synthesized nanomaterials were verified using Fourier-transform infrared spectroscopy (FTIR). Surface morphology was assessed using scanning electron microscopy (SEM) whereas purity, shape and size of the crystallite were determined using X-ray diffraction (XRD) technique. The potential of these nanomaterials to degrade three dyes i.e., Reactive Red-2 (RR-2), Reactive Black-5 (RB-5) and Orange II sodium salt (OII) azo dyes, was determined in an aqueous medium under visible light (photocatalysis). The photodegradation effectiveness of all nanomaterials was evaluated under different factors like nanomaterial dose (0.02–0.1 g 10 mL−1), concentration of dyes (20–100 mg L−1), and irradiation time (60–120 min). They were also assessed for their potential to adsorb RR-2 and OII dyes.ResultsResults revealed that at optimum concentration (60 mgL−1 CuO-NPs. The highest degradation potential shown by the nanocomposite was attributed to its large surface area, small particles size, and quick reactions which were proved by advance analytical techniques. The equilibrium and kinetic adsorption of RR-2 and OII on NiO-NPs, CuO-NPs, and NiO/CuO-NC were well explained with Langmuir and Pseudo second order model, respectively (R2 ≥ 0.96). The maximum RR-2 adsorption (103 mg/g) was obtained with NiO/CuO-NC. It is concluded that nanocomposites are more efficient and promising for the dyes degradation from industrial wastewater as compared with dyes adsorption onto individual NPs. Thus, the nanocomposite NiO/CuO-NC can be an excellent candidate for photodegradation as well as the adsorption of the dyes in aqueous media.

【 授权许可】

CC BY