Adsorption of uranium (VI) from aqueous solutions using boron nitride/polyindole composite adsorbent

Abstract

Turbostratic boron nitride (tBN) surface is modified with polyindole (PIn) by a facile polymerization technique and the uranyl adsorption efficiency of this mesoporous hybrid is investigated. The successful surface modification is confirmed by FT‐IR, Raman, XRD, TEM, SEM, EDX, EDS mapping XPS, BET, and zeta potential techniques. The batch experiments are performed in various temperatures (T), contact times (t), pH, and initial solution concentrations (C0) to evaluate its adsorption performance. The optimum adsorption performance is achieved at pH = 5.0–5.5, T = 307 K, t = 10 min, C0 = 18 mg L−1. These experimental results are evaluated using Freundlich, Redlich–Peterson, and Langmuir isotherm models, which presents equivalent regression coefficients. Maximum adsorption capacity (qm) of the nanoadsorbent (tBN/PIn), determined by the Langmuir isotherm, is 315.29 mg g−1. The adsorption kinetics of uranyl ions on tBN/PIn are in harmony with the pseudo‐second order model. tBN/PIn nanoadsorbent provides high adsorption efficiency even at exceptionally low UO22+ concentration range (4–40 mg L−1) and low adsorbent mass (0.005 g). XPS analysis results show that 0.05% of uranium is adsorbed on tBN/PIn via mainly U‐O coordination. The results of present study demonstrate that tBN/PIn can a potential adsorbent for removing uranium from aqueous solutions.

Methods for Preparation of Hexagonal Boron Nitride Nanomaterials

“…369 Pb(II), 370 Cr(VI), 371 and uranium(VI). 372 Furthermore, active porous h-BN architecture also exhibits excellent removal performance for dyes, oil pollutants, and antibiotics in water. 27,66,334 BNNSs with small size and high surface area are more easily dispersed in water, increasing the contact opportunities with water pollutants and resulting in faster adsorption rates.…”

“…For instance, compared to carbon-based adsorbents, BN shows stronger adsorption capacity for heavy metal ions due to the polar B–N bonds, asymmetrical density characteristics of ionic bonds, and more electron transfer to metal ions. Therefore, BN nanomaterials exhibit good adsorption of various metal ions in water, such as Hg(II), Pb(II), Cr(VI), and uranium(VI) . Furthermore, active porous h -BN architecture also exhibits excellent removal performance for dyes, oil pollutants, and antibiotics in water. ,, BNNSs with small size and high surface area are more easily dispersed in water, increasing the contact opportunities with water pollutants and resulting in faster adsorption rates.…”