Efficient Removal of Cr(VI) Ions by a Novel Magnetic 4-Vinyl Pyridine Grafted Ni₃Si₂O₅(OH)₄ Multiwalled Nanotube

Abstract

The contamination of water systems by heavy metals greatly threatens human health and ecological safety. An efficient adsorbent is critical for the removal of these contaminants. In this work, magnetic Ni 3 Si 2 O 5 (OH) 4 nanotubes (NTs) have been synthesized via in situ hydrothermal reduction and further functionalized by grafting poly(4-vinyl pyridine) (P4VP) brushes on its surface via atom transfer radical polymerization. Characterizations by Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, and X-ray photoelectron spectroscopy proved that P4VP was successfully grafted on the surface of magnetic Ni 3 Si 2 O 5 (OH) 4 NTs. The resultant Ni 3 Si 2 O 5 (OH) 4 - g -P4VP NTs are efficient nanosorbents for removing Cr(VI) anions from water. The Cr(VI) adsorption capacity of Ni 3 Si 2 O 5 (OH) 4 - g -P4VP NTs reaches 1.49 mmol/g at a pH of 3. The pseudo-second-order kinetic model and the Freundlich isothermal model are suitable to describe the adsorption process. The analysis using Weber–Morris and Boyd models indicates that both intraparticle diffusion and external film diffusion affect the Cr(VI) adsorption process. The adsorption enthalpy is estimated to be 18.37 kJ/mol. More than 90% of the Cr(VI) adsorption capacity of the Ni 3 Si 2 O 5 (OH) 4 - g -P4VP NTs remains after eight adsorption and desorption cycles.

Elevating the comprehensive performance of carbon-based hybrid electrode materials by incorporating nickel silicate for lithium-ion capacitors

“…1f show lattice fringes corresponding to (100), (101), and (002) planes of Ni(OH) 2 and (110) plane of Ni 3 Si 2 O 5 (OH) 4 . 30,31 These results reveal the coexistence of Ni(OH) 2 and Ni 3 Si 2 O 5 (OH) 4 in the surface nanosheets of NiSiC.…”

Surface Molecularly Imprinted Cellulose‐Synthetic Hybrid Particles Prepared via ATRP for Enrichment of Flavonoids in Olive Leaf

“…The pyridyl group behaves as a proton acceptor (small nucleophilic molecule that can interact with exposed electrophilic residues), being also a good ligand for multiple metal ions, giving rise to complexation. Due to these particular properties, polymers based on 4VP are being considered for heavy metals ions adsorption and wastewater/industrial effluents treatment, [13][14][15][16][17] enzymes/protein adsorption, [18,19] and other applications involving electronics, biomedicine, or catalysis. [20] Experimental runs reported in Table 1 lead to products with different features concerning synthetic functionalization and morphology, impacting their use with sorption/desorption processes.…”

Anion exchange material based on polyvinylchloride and urea for the removal of chromium(vi) ions from aqueous solutions

“…[ 1,2 ] Chromium exists in two oxidation states in aqueous solution, namely, trivalent Cr(III) and hexavalent Cr(VI). [ 3–6 ] Excessive intake of chromium can cause various severe diseases, although Cr(III) is one of the essential microelements for the human body. Chromium(VI) is highly toxic due to its mutagenic and carcinogenic activity.…”