Hierarchical Nanoflowers of MgFe2O4, Bentonite and B-,P- Co-Doped Graphene Oxide as Adsorbent and Photocatalyst: Optimization of Parameters by Box–Behnken Methodology

Abstract

In the present study, nanocomposites having hierarchical nanoflowers (HNFs) -like morphology were synthesized by ultra-sonication approach. HNFs were ternary composite of MgFe2O4 and bentonite with boron-, phosphorous- co-doped graphene oxide (BPGO). The HNFs were fully characterized using different analytical tools viz. X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersion spectroscopy, transmission electron microscopy, X-ray diffraction, vibrating sample magnetometry and Mössbauer analysis. Transmission electron micrographs showed that chiffon-like BPGO nanosheets were wrapped on the MgFe2O4-bentonite surface, resulting in a porous flower-like morphology. The red-shift in XPS binding energies of HNFs as compared to MgFe2O4-bentoniteand BPGO revealed the presence of strong interactions between the two materials. Box–Behnken statistical methodology was employed to optimize adsorptive and photocatalytic parameters using Pb(II) and malathion as model pollutants, respectively. HNFs exhibited excellent adsorption ability for Pb(II) ions, with the Langmuir adsorption capacity of 654 mg g−1 at optimized pH 6.0 and 96% photocatalytic degradation of malathion at pH 9.0 as compared to MgFe2O4-bentonite and BPGO. Results obtained in this study clearly indicate that HNFs are promising nanocomposite for the removal of inorganic and organic contaminants from the aqueous solutions.

Metal–Organic Frameworks Meet Metallic Oxide on Carbon Fiber: Synergistic Effect for Enhanced Photodegradation of Antibiotic Pollutant

“…However, the potential of +2.38 eV and +2.72 eV for OH − to ·OH and H 2 O to ·OH were higher than that of the photocatalysts. The band alignments versus the normal hydrogen electrode (NHE) were indicated in Figure 6 e. The possible formation procedure of ·OH was attributed to the O 2 due to the potential energy of +0.695 eV for O 2 to H 2 O 2 , which subsequently was transformed to ·OH with the capture of electrons [ 51 , 52 ]. The results showed reactive species in this photocatalytic system including O 2 − , H+, and ·OH, which coincided with the ESR of the photocatalysts.…”

Solid Fe Resources Separated from Rolling Oil Sludge for CO Oxidation

“…XPS spectra of Fe 2p of samples before and after CO pretreatment are presented in Figure 6 . The peaks at 710.97 and 724.45 eV are assigned to Fe 2p 3/2 and Fe 2p 1/2 , respectively, and the satellite peak at 719.16 eV is attributed to Fe 2 O 3 [ 36 , 37 ]. No peaks assigned to Fe 0 and Fe 2+ were detected, as expected.…”

A Review on Impacting Parameters for Photocatalytic Degradation of Organic Effluents by Ferrites and Their Nanocomposites

“…Similar results were found when the hierarchical nanoflowers of the MgFe 2 O 4 , Bentonite and B-, Pco-doped Graphene Oxide were tested for their reusability and stability. The degradation efficiency was found to be decreased by only 5% after 5 consecutive cycles [83].…”

“…Hierarchical nanoflowers of MgFe 2 O 4 , bentonite and boron, phosphorous co-doped graphene oxide synthesized using the ultrasonication method showed that chiffon-like co-doped graphene oxide nanosheets were wrapped on the MgFe 2 O 4 -bentonite surface, resulting in a porous flower-like morphology. The excellent conductivity of the co-doped nanosheets allowed for a quick charge carrier transport, which aided in the separation of those carriers during the photocatalytic reaction [83]. Cationic surfactant cetyltrimethyl ammonium bromide was chosen to coat the MgFe 2 O 4 because its negatively charged surface can interact with the surfactant during ultrasonication [84].…”

“…The CuRu x Fe 2−x O 4 showed an increase in the photocatalytic efficiency, which was found to be 92% for x = 0.02, whereas with further substitution up to x = 0.06 and x = 0.1, the degradation time reached 120 min and 90 min, respectively. Similarly, when the Ti content in the ternary-doped Sr 1−x Ti x Fe 2 O 4+δ ferrite was increased from 0.3 to 0.6, the band gap was decreased from 2.45 to 2.18 eV, which increased the charge carrier concentration and decreased the barrier height from 1.20 to 1.02 eV, compared to the pure SrFe 2 O 4 and TiFe 2 O 5 [83]. These features were very helpful for the degradation of the p-nitrophenol, pendimethalin and martius yellow with apparent rate constant values 1.9 × 10 −2 min −1 , 2.3 × 10 −2 min −1 , and 1.3 × 10 −2 min −1 , respectively.…”