A Hydrofluoric Acid-Free Green Synthesis of Magnetic M.Ti 2 CT x Nanostructures for the Sequestration of Cesium and Strontium Radionuclide.
Jibran IqbalKashif RasoolFares M HowariYousef NazzalTapati SarkarAsif ShahzadPublished in: Nanomaterials (Basel, Switzerland) (2022)
MAX phases are the parent materials used for the formation of MXenes, and are generally obtained by etching using the highly corrosive acid HF. To develop a more environmentally friendly approach for the synthesis of MXenes, in this work, titanium aluminum carbide MAX phase (Ti 2 AlC) was fabricated and etched using NaOH. Further, magnetic properties were induced during the etching process in a single-step etching process that led to the formation of a magnetic composite. By carefully controlling etching conditions such as etching agent concentration and time, different structures could be produced (denoted as M.Ti 2 CT x ). Magnetic nanostructures with unique physico-chemical characteristics, including a large number of binding sites, were utilized to adsorb radionuclide Sr 2+ and Cs + cations from different matrices, including deionized, tap, and seawater. The produced adsorbents were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The synthesized materials were found to be very stable in the aqueous phase, compared with corrosive acid-etched MXenes, acquiring a distinctive structure with oxygen-containing functional moieties. Sr 2+ and Cs + removal efficiencies of M.Ti 2 CT x were assessed via conventional batch adsorption experiments. M.Ti 2 CT x -A III showed the highest adsorption performance among other M.Ti 2 CT x phases, with maximum adsorption capacities of 376.05 and 142.88 mg/g for Sr 2+ and Cs + , respectively, which are among the highest adsorption capacities reported for comparable adsorbents such as graphene oxide and MXenes. Moreover, in seawater, the removal efficiencies for Sr 2+ and Cs + were greater than 93% and 31%, respectively. Analysis of the removal mechanism validates the electrostatic interactions between M.Ti 2 C-A III and radionuclides.
Keyphrases
- dual energy
- electron microscopy
- computed tomography
- high resolution
- image quality
- molecularly imprinted
- contrast enhanced
- magnetic resonance imaging
- positron emission tomography
- aqueous solution
- ionic liquid
- solid phase extraction
- heart failure
- single molecule
- oxidative stress
- diabetic rats
- liquid chromatography
- anaerobic digestion