An ethylene glycol intercalated monometallic layered double hydroxide based on iron as an efficient bifunctional catalyst

Abstract

Given the fact that the literature describing the intercalation of organic molecules in monometallic LDH systems is scarce, the present investigation is aimed at the generation of ethylene glycol intercalated Fe-Fe LDH with the objective of enhancing the surface area for further catalytic applications of industrially important and environmentally harmful organics. The solvothermal reaction of FeCl with urea in an ethylene glycol medium yielded a brown colored powder which was characterized employing a wide range of analytical techniques including high resolution powder X-ray diffraction (PXRD), scanning electron microscopy, thermal analysis, X-ray photo electron spectroscopy (XPS), elemental (C, H, N and S) analysis, UV-visible, photoluminescence spectroscopy measurements, BET surface area and pore-size analysis. The observed reflections in the PXRD pattern were indexed in a rhombohedral symmetry with a = 3.175 and c = 31.9 Å. Combining the results from the Fe 2p core level analysis and anion contents from elemental and thermogravimetric analysis, a formula of Fe Fe (OCH) (OH) was deduced for the sample. The intercalation of EG in the interlayer was confirmed from FTIR and Raman spectroscopy measurements. The d-d transitions of the Fe-ion and the charge transfer transition of the Fe(ii)-Fe(iii) lattice were evident in the UV-visible spectrum. Blue indigoid emission bands arising from the transitions present in the Fe-ion were noticed in the photoluminescence spectrum. The measured BET surface area and pore diameter of the sample were 144 m g and 12.5 nm, respectively. Almost instant decolourisation of the Xylenol Orange (XO) dye occurred in the presence of HO and the LDH sample as catalyst. Similar observations were encountered for Methyl Orange (MO) and Methylene Blue (MB) dyes. All these reactions followed pseudo first-order kinetics. The industrially important reductive conversion of nitro aromatics was catalyzed by the sample. The selective reduction of 2,4-dinitrophenol to 2-amino-4-nitrophenol was effected almost instantaneously by this catalyst. Both the reusability and possible mechanism of catalytic action have been discussed. The EG intercalated Fe-Fe LDH influenced the relaxivity value of protons as determined from NMR spectroscopy experiments.

Fabrication of a recyclable magnetic halloysite-based cobalt nanocatalyst for the efficient degradation of bisphenol A and malachite green

“…Moreover, peaks at 711.35 (Fe 2p 3/2 ) and 724.57 eV (Fe 2p 1/2 ) are in well accordance with trivalent state of iron, affirming the successful decoration of Fe 3 O 4 NPs on HNTs surface. 61,62 Besides, the core level spectrum of Co 2p exhibits binding energy peaks at 780.79 eV and 786.87 eV which matches well with the Co 2p 3/2 , while peak at 796.53 eV and 802.94 eV are correspondingly attributed to Co2p 1/2 , that confirms the existence of +2 oxidation state of cobalt in Co(II)@2-BPy@APTES@MHNTs. 63,64 Compositional analysis EDS and ED-XRF are the powerful tools that provides the information related to the elemental composition of discrete elements present in synthesized nanocomposites.…”

Metastable Bi2Zr2O7 with Pyrochlore-like Structure: Stabilization, Oxygen Ion Conductivity, and Catalytic Properties

“…While a major thrust has been centered on the use of fluorite-structured oxides as oxidation catalyst, their capability to promote reduction reactions, preferably organic substrates, has not yet been explored extensively. ,, The production of nitroaromatics in pharmaceutical industries has been known to be a major threat to environment, and conversion of nitroaromatics to harmless chemicals could address the environmental concerns as well as add value to the economy. For example, aminophenols have been extensively used in analgesic and antipyretic drugs as well as photographic developer, corrosion inhibitor, anticorrosion lubricant, etc. − Because of this, reduction of nitrophenols has a significant role in the development of modern industries. With this basis, applicability of the titled sample as catalyst for the reduction of nitroaromatics such as nitrophenols (ortho-, meta-, and para-), nitroaniline (ortho-, meta-, and para-) was examined.…”

Catalytic Application of Oxygen Vacancies Induced by Bi3+ Incorporation in ThO2 Samples Obtained by Solution Combustion Synthesis

“…The applicability of these three samples for the oxidative decolorization of dye molecules, MO and XO has been examined. As the absorbance maxima of MO and XO occurred at 500 and 430 nm, respectively, progress of the reaction was monitored by measuring the absorbance maxima with time. − From the results shown in Figures and , it was found that nearly 89 and 88% of MO and XO were decolorized in 30 and 20 min, respectively, employing Th 0.50 Bi 0.50 O 2−δ sample prepared from solution combustion synthesis. The pseudo first-order rate constants extracted for these heterogeneous reactions were 0.0701 min –1 (for MO) and 0.0642 min –1 (for XO).…”