Synthesis and Characterization of Novel Hybridized CeO₂@SiO₂ Nanoparticles Based on Rice Husk and Their Application in Antibiotic Removal

Abstract

This work aims to synthesize a core–shell material of CeO2@SiO2 based on rice husk as a novel hybridized adsorbent for antibiotic removal. The phase structures of CeO2@SiO2 and CeO2 nanoparticles that were fabricated by a simple procedure were examined by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared (FT-IR) spectroscopy, while their interfacial characterizations were performed by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), the Brunauer–Emmett–Teller (BET) method, and ζ-potential measurements. The removal efficiency of the antibiotic amoxicillin (AMX) using CeO2@SiO2 nanoparticles was much greater than that using SiO2 and CeO2 materials in solutions of different pH values. The optimum conditions for AMX removal using CeO2@SiO2 including contact time and adsorbent dosage were 120 min and 5 mg/mL, respectively. The maximum AMX removal using CeO2@SiO2 reached 100% and the adsorption capacity was 12.5 mg/g. Adsorption isotherms of AMX onto CeO2@SiO2 were fitted by Langmuir, Freundlich, and two-step adsorption models, while the adsorption kinetics of AMX achieved a better fit by the pseudo-second-order model than the pseudo-first-order model. The electrostatic and nonelectrostatic interactions between the zwitterionic form of AMX and the positively charged CeO2@SiO2 surface were controlled by adsorption. The effects of different organics such as humic acid, ionic surfactants, and pharmaceutical substances on AMX removal using CeO2@SiO2 were also thoroughly investigated. The high AMX removal efficiencies of about 75% after four regenerations and about 70% from an actual water sample demonstrate that CeO2@SiO2-based rice husk is a hybrid nanomaterial for antibiotic removal from water environments.

Adsorptive Removal of Anionic Azo Dye New Coccine Using Silica and Silica-gel with Surface Modification by Polycation

“…The adsorbent dosage inducing the total surface area of adsorbent and the net surface charge [2,17] highly influence to adsorption process.…”

“…Different techniques have been investigated and further developed for treatment to remove dyes from aqueous solution [3,4], such as photocatalysis [5][6][7], advanced oxidation [8,9], flocculation and coagulation [10], biological processes [11], and adsorption [12][13][14][15]. For developing countries, adsorption is one of the most suitable and effective methods for dye removal when using low-cost adsorbents such as minerals, clays or agricultural subproducts [2,16,17]. Various hybridized materials have been investigated for removal of dye through adsorption techniques, such as nanofibrous membrane [18] or porous g-C 3 N 4 nanosheet [19].…”

Synthesis of succinylated carboxymethyl starches and their role as adsorbents for the removal of phenol

“…4a. The spectra showed a peak at (1) DS = area of C-7,8 proton of succinylated part/4 area of C-1a,b proton of starch backbone 3420 cm −1 was attributed to the -OH vibration [48] of the glucose unit. Similarly, the peaks that appeared at 2927 cm −1 and 1615 cm −1 were assigned to the -CH 2 stretching vibration and -CO-group of the CMS, respectively [49].…”

Removal of Cd(II) from Micro-Polluted Water by Magnetic Core-Shell Fe3O4@Prussian Blue

“…The adsorption capacity of several adsorbents has been proved to be significantly improved by surface modification [ 38 , 39 , 40 , 41 ]. Inspired by this, this study aimed to synthesize core-shell MPB spheres (Fe 3 O 4 @PB) to be used as adsorbent materials to remove Cd (II) species from micro-polluted water.…”