l-Cysteine-Functionalized Mesoporous Magnetite Nanospheres: Synthesis and Adsorptive Application toward Arsenic Remediation

Abstract

Water pollution and its hazardous effects due to inadequate disposal of toxic arsenic (As) species is a severe environmental concern globally. In the present study, magnetic Fe 3 O 4 nanoparticles (NPs) functionalized with L-cysteine (Fe 3 O 4 @ Cy) were synthesized by a simple surfactant-assisted solvothermal method followed by a post-treatment process. The surface functionalization of Fe 3 O 4 NPs with L-cysteine (L-Cy) not only improves their stability but also enhances the As adsorption efficiency. The synthesized materials were extensively characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, vibrating sample magnetometer (VSM), thermogravimetric analyzer (TGA), ζ-potential, nitrogen adsorption−desorption, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM) techniques. The mesoporous Fe 3 O 4 @Cy exhibited superior adsorption capacities of 20.00 and 34.00 mg/g for arsenite (As(III)) and arsenate (As(V)) ions, respectively. The kinetics and isotherm studies reveal that the adsorption process follows pseudo-second-order and Langmuir isotherm models. Also, from the thermodynamic study, it is clear that the adsorption process is spontaneous and endothermic in nature. FTIR spectroscopy, FE-SEM, energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) techniques provided insights into the adsorption mechanism.

Bio-inspired membranes for adsorption of arsenic via immobilized L-Cysteine in highly hydrophilic electrospun nanofibers

“…L-Cys-based surfactants have also been synthesized as an environmentally friendly and biodegradable material with a cysteine headgroup for selective As(V) binding in water treatment (Makavipour et al, 2019). The surface functionalization of magnetic nano-magnetite nanoparticles with L-Cys (Fe 3 O 4 @Cy) presented improved stability and enhanced arsenite and arsenate adsorption efficiency (Tripathy et al, 2020). The arsenic removal efficiency in these previous works ranged from 27% to 75%, and the adsorption process required long contact times.…”

Hollow carbon spheres for diclofenac and venlafaxine adsorption

“…Considering the water contamination concern, adsorption is considered one of the most adequate and applicable techniques for pollutant removal due to its simplicity and easy operation [11]. Carbon nanomaterials (NMs) have been used as sorbents because they possess a high surface area-to-volume ratio that usually guarantees much greater adsorption capacity, as well as the possibility to easily modify their surface chemistry to improve the selectivity towards the target adsorbates [12].…”

“…Carbon nanomaterials (NMs) have been used as sorbents because they possess a high surface area-to-volume ratio that usually guarantees much greater adsorption capacity, as well as the possibility to easily modify their surface chemistry to improve the selectivity towards the target adsorbates [12]. In fact, NMs can strongly adsorb many substances including trace metals and polar organic compounds [11,12].…”