Magnetic Fe3O4–FeB nanocomposites with promoted Cr(VI) removal performance

Abstract

In this study, amorphous FeB alloy modified magnetitenanocomposites (Fe 3 O 4-FeB) were facilely synthesized by interfacialreduction of commercialFe 3 O 4 nanoparticles with NaBH 4. TEM, CS-STEM integrated with EDS, Mössbauer spectroscopyanalysis confirmed the formation of Fe 3 O 4-FeB, where a shell of amorphous FeB nanoparticles with 2-4 nm in size was surrounded on the inner magnetite Fe 3 O 4 part.Fe 3 O 4-FeB displayed a promotedCr(VI)removal efficiency compared withthe bare Fe 3 O 4 counterpart, the interfacial reduced Fe 3 O 4 nanoparticles with hydrogen and/or with hydrazine hydride. XPS analysis evidenced that reduction of Cr(VI) on surface of the Fe 3 O 4-FeB was the major contribution to the Cr(VI) removal. Tafel polarization analysis of the Fe 3 O 4-FeB and aqueous boron speciesmeasurement indicated thathigh Cr(VI) removal efficiencywith Fe 3 O 4-FeB was highly depended on amorphous FeB alloy shell, in which boron element containing free electrons could accelerate the electron transfer from Fe to the adsorbed Cr(VI), as well reduce Fe(III) to Fe(II) and thus promote the Fe(III)/Fe(II) cycles.The efficient Cr(VI) removal under a wide range of pH values and its easy magnetic separationmake the Fe 3 O 4-FeB be a potential for Cr(VI) contaminated water

Chemical Synthesis of High-Stable Amorphous FeCo Nanoalloys with Good Magnetic Properties

“…As shown in Figure 6D, the B 1s spectra for two amorphous samples also exhibit very similar curves and peak locations, which indicate the same B element state. The B 1s peaks at 192.1 and 187.9 eV can be attributed to the existence of FeB or CoB phases on surface of the amorphous samples [39,40]. The slight shift of peak location of 0.6 eV in XPS narrow-scan spectra for the two amorphous samples can be ascribed to of their different surface compositions, which are verified by the EDS investigation in Table 1.…”

Insight into pH dependent Cr(VI) removal with magnetic Fe3S4

“…The concentration of Cr(VI) in aqueous solution was measured by using 1,5-diphenylcarbazide method [41], which was not sensitive to Cr (III) species. Chromium reagent, 1,5-diphenylcarbazide, was mixed with 0.5 mL of filtrate for 5 min.…”

Self‐emulsion polymerization of amphiphilic monomers—a green route to synthesis of polymeric nanoscaffolds

“…The peaks corresponding to 710 and 723.5 eV can be attributed to Fe in +2 oxidation state, while peaks at 711.9 and 725.7 eV are from Fe in +3 oxidation state. Furthermore, the appearance of the satellite peak at 8 eV higher than the main 2p 3/2 peak is also an indication of the presence of Fe 2 O 3 . Thus, XRD and XPS data suggested the coexistence of Fe 3+ and Fe 2+ states in the nanohybrid.…”