Synthesis and characterization of hexagonal boron nitride used for comparison of removal of anionic and cationic hazardous azo-dye: kinetics and equilibrium studies.

Tuba Tarhan

doi:10.3906/kim-2004-23

Abstract

The purpose of this study was to compare the adsorption behavior of cationic and anionic dyes onto a hexagonal boron nitride (hBN) nanostructure that was rich in a negative charge. Herein, the hBN nanostructure was synthesized using boric acid as a precursor material. The characteristic peaks of the hBN nanostructure were performed using Fourier transform infrared (FT-IR) and Raman spectroscopies. The morphology and the particle size of hBN nanostructure were determined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). During the studies, various essential adsorption parameters were investigated, such as the initial dye concentration, pH of the dye solution, adsorbent dose, and contact time. Under optimal conditions, the removal of 42.6% Metanil yellow (MY) and 90% Victoria blue B (VBB) from aqueous solution was performed using a 10-mg hBN nanostructure. Furthermore, the equilibrium studies showed that the Freundlich isotherm model fitted well for the removal of MY. However, the Langmuir isotherm model fitted well for the removal of VBB. Moreover, according to the results obtained from the kinetic studies, while the first-order kinetic model was suited for the adsorption of the MY, the second-order kinetic model was found to well fit for the adsorption of VBB.

Highlights

In the modern age, unnecessary industrial and anthropological activities cause numerous problems related to the environment
The FTIR spectra of the hexagonal boron nitride (hBN) and hBN-dye conjugates are given in Figures 2a and 2b, where it can be seen that the characteristic peaks of the organic dyes were not observed on the spectra of the hBN-dye conjugates because the hBNs had strong and wide characteristic peaks
The peak intensities of the spectra of the hBN-dye conjugates significantly decreased when compared with the pristine hBN nanostructure after dye adsorption

Summary

Introduction

Unnecessary industrial and anthropological activities cause numerous problems related to the environment. Despite the fact that researchers are working very hard on these environmental problems, the problems of water, air, and soil pollution remain an issue [3,4,5]. These environmental problems arise due to the largescale production of synthetic and organic materials [6]. These pollutants are widely used in leather, textile, shoe polish, dyeing and printing, colored water-fast inks, paper, cosmetic, and pharmaceutical industries. There is much research being conducted in this area

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