Boron Nitride Nanosheets Functionalized with Fe₃O₄ and CoFe₂O₄ Magnetic Nanoparticles for Nanofiltration Applications

Abstract

Nanofiltration (NF) is one of the emerging technologies that is very promising for water purification among many other applications. 2D boron nitride (BN) based nanomaterials are excellent building blocks for NF membranes. In our work, BN nanosheets (BNNS) have been functionalized with magnetic nanoparticles (MNPs) to form BNNS–MNP nanocomposites. It was found that the nanocomposites are stable with the MNPs giving very good coverage with both magnetite and cobalt ferrite MNPs and showing good attachment and stability to sonication. These nanocomposites have been tested for removal of methylene blue (MB) dye and MNPs from water. BNNS–magnetite nanocomposites showed higher removal efficiency of the MB from water than the corresponding pure BNNS, while the BNNS–cobalt ferrite removal efficiency was slightly less than the pure BNNS. The BNNS–cobalt ferrite material was regenerated by burning off the MB and recycled to show the recyclability of this material. The BNNS membranes were tested for filtration of 14 ± 4 nm magnetite MNPs and were found to capture 100% of the nanoparticles with no MNPs left in the filtrate. Thus, we have developed magnetic nanocomposite membranes, which have demonstrated great potential for water remediation. We believe that this research opens up promising ways for production of 2D nanocomposite materials with multiple applications.

Boron Nitride Nanosheet–Magnetic Nanoparticle Composites for Water Remediation Applications

“…This alteration aligns with the anticipated outcome when the ferrite interacts with the BN flakes. This result is also in line with our previous result where for BNNS-Fe 3 O 4 and BNNS-CoFe 2 O 4 , a similar shift was seen . These shifts indicate new interactions, which affect the out-of-plane and the in-plane vibration of the BNNS.…”

“…The shifting of the B 1s peaks toward higher binding energies upon formation of the B-metal interactions, 191.87 and 191.28 eV respectively, indicates that there is a net movement of electron density from the B sites to the metal centers. The peak position for the B–Mn interaction is at a lower binding energy as compared to the B–Fe contribution, while in our previous paper, the B–Co contribution was at a higher binding energy with respect to the B–Fe interaction . This can be attributed to the changing electronegativity of Mn (1.55), Fe (1.83), and Co (1.91) with Co showing the largest shift.…”

“…BNNS-MnFe 2 O 4 has higher surface area relative to the uncoated BNNS which can be attributed to the additional surface area contribution of the MnFe 2 O 4 nanoparticles. This value was higher than our previously reported surface area values for BNNS-Fe 3 O 4 (38.8 m 2 /g) and BNNS-CoFe 2 O 4 (34.6 m 2 /g) …”

“…This work in combination with our previous work show that MNP can be attached to the BNNS directly without the need for organic linkers. The BNNS and the BNNS-MNP nanocomposites can be used for water filtration, with the addition of the MNP to the BNNS surface increasing the adsorption capacity when MnFe 2 O 4 MNPs are used.…”

“…BNNS-MNP nanocomposites have been synthesized using protocols previously developed by our group . We prepared BNNS with MnFe 2 O 4 nanoparticles on the surface of the nanosheets (Scheme ).…”