One-step synthesis of magnetic 1,6-hexanediamine-functionalized reduced graphene oxide–zinc ferrite for fast adsorption of Cr(vi)

Abstract

A one-step solvothermal method was developed to prepare nearly cubic ZnFe 2 O 4 nanoparticles loaded on 1, 6-hexanediamine-functionalized reduced graphene oxide (HDA-RGO-ZnFe 2 O 4 ) for fast removing Cr (VI). The materials were characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Raman, and vibrating sample magnetometry. Experimental results indicated that Cr (VI) adsorption by HDA-RGO-ZnFe 2 O 4 is strongly pH dependent and the adsorption equilibrium could be reached within 12 min. The kinetic adsorption of different initial concentrations can be accurately described by the pseudo-second-order model. The overall rate process was apparently influenced by external mass transfer and intraparticle diffusion. The Langmuir isotherm model is consistent with the experimental data at different temperatures and the maximum adsorption capacity was determined to be 172.4 mg g -1 . Moreover, the thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The adsorption mechanism and desorption experiments were also studied. After adsorption, the HDA-RGO-ZnFe 2 O 4 could be quickly separated from the media by an external magnetic and the adsorption capacity can remain up to 82% after five times of usage. The results implied that HDA-RGO-ZnFe 2 O 4 is a promising adsorbent for the removal of Cr (VI).

Facile Microwave Hydrothermal Synthesis of ZnFe2O4/rGO Nanocomposites and Their Ultra-Fast Adsorption of Methylene Blue Dye

“…The measurements of ZF and ZFG nanoparticles showed two distinct peaks at 520 cm −1 and 381 cm −1 . These two peaks correspond to the stretching vibration of the Zn-O bond at the tetrahedral position and the Fe-O bond at the octahedral position, respectively [ 63 , 65 ].…”

Potential utility of graphene-based nano spinel ferrites as adsorbent and photocatalyst for removing organic/inorganic contaminants from aqueous solutions: A mini review

“…The observed difference in q m is ascribed to the nature of cations deposited in GNSFs. Similarly, different q m values for Cr(VI) ions observed depending on different types of cations, being 501, 136, and 172 mg g −1 for poly(m-phenylenediamine)/rGO/NiFe 2 O 4 (PmPD/rGO/NFO) (Wang et al, 2017b), amino-functionalized SiO 2 @CoFe 2 O 4 -GO (Santhosh et al, 2017), and 1,6-hexanediamine-functionalized rGO/ZnFe 2 O 4 (HDA-rGO-ZnFe 2 O 4 ) (Li et al, 2015), respectively. Numerous studies have employed bare/polymer-grafted magnetic nanoparticles or similar graphene-based magnetic composites to remediate toxic heavy metals and organic dyes.…”

“…Wang et al (2017b) reported that the electrostatic interaction between negatively charged Cr(VI) species and the protonated PmPD/rGO/NFO played an important role in Cr(VI) adsorption at pH = 3. Li et al (2015) observed that HDA-rGO-ZnFe 2 O 4 had better removal performances for Cr(VI) under acidic conditions, in which the protonated amine groups (__NH 3 + ) of HDA would attract the negatively-charged Cr(VI) species electrostatically. In addition, the adsorbed Cr(VI) was reduced to Cr(III) and bound to the negatively-charged carboxylic groups of HDA-rGO-ZnFe 2 O 4 through electrostatic interaction, which was confirmed by XPS analysis.…”

Heterostructured ZnFe2O4/TiO2 nanocomposites with a highly recyclable visible-light-response for bisphenol A degradation

“…More recently, a particular interest in the development of visible-light-responsive photocatalysts is the synthesis of nanocrystalline spinel ferrite. Spinel ferrites including NiFe 2 O 4 , ZnFe 2 O 4 and CuFe 2 O 4 have possessed unique photocatalytic properties for the removal of inorganic contaminants, [9][10][11] antimicrobial activity 12 and organic dyes. [13][14][15][16][17] In addition, the spinel crystal structure of ferrites offers the available extra catalytic sites by virtue of the crystal lattices and a band gap capable of absorbing visible light to enhance the photodegradation efficiency of pollutants.…”