Synthesis of Transition Metal Doped ZnO Nanoparticles for Its use as an Adsorbent for Waste Water Treatment
Synthesis of Transition Metal Doped ZnO Nanoparticles for Its use as an Adsorbent for Waste Water Treatment
Santosh Kumar
Department of Physics,
College of Commerce, Arts and Science, Patna-800020
Email id: skphysics@yahoo.co.in
ABSTRACT
Cr-doped ZnO nanoparticles (NPs) having different contents of Cr3+ have been synthesized by solvothermal method. The as-prepared products have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). In accordance with the adsorption capacity of the products, the obtained optimal Cr/Zn molar ratio is 6%. The adsorption process of Methyl Orange (MO) on Cr-doped ZnO was investigated by kinetics, thermodynamics, and isotherm technologies, which, respectively, indicated that the adsorption was fast. The adsorption reached equilibrium in 2 h and it agreed well with the Langmuir isotherm with a maximum adsorption capacity of 310.56 mg g−1. Moreover, a reasonable mechanism was proposed to elucidate the reasons for their adsorption behavior. In addition, a simple and low-cost chemical method was developed to separate and recycle ZnO and MO from the used adsorbent, effectively avoiding the secondary pollution. This work can not only describe efficient experimental approaches for obtaining novel adsorbents and recycling them but also offer valuable clues for the preparation and property study of other semiconductor adsorbents.
KEYWORDS: Cr-doped ZnO, adsorption, methyl orange, kinetics, isotherm
Paper History: Paper Received on 30/07/2017, Accepted on 2/12/2017, Published on 20/12/2017