scholarly journals Synthesis and characterization of binary and ternary hydrotalcites-like compounds for the hydroxylation of phenol

2017 ◽  
Author(s):  
◽  
Sindisiwe Fortunate Muthwa
Keyword(s):  
Surface Area ◽  
Copper Concentration ◽  
Internal Standard ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Icp Oes ◽  
Hydroxylation Of Phenol ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Phenol Conversion

Hydrotalcites (HT) and hydrotalcites-like (HTLc) compounds were synthesized by the co-precipitation method under low supersaturation. The synthesized binary Mg-Al hydrotalcites and ternary Cu/Mg-Al hydrotalcite-like compounds were characterized by various physico-chemical techniques such as inductively coupled plasma-optical emission spectroscopy (ICP-OES), powder X-ray diffraction (XRD), Fourier transform- infrared spectroscopy (FT-IR), ultraviolet-visible (UV-VIS) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and BET surface area analysis. Elemental composition generated from ICP-OES data revealed a value of x in the region of 0.25 to 0.33 for all the compounds except for the MgAl-11 sample which revealed an x value of 0.5 while XRD patterns exhibited characteristic features indicative of an ordered layered material. FT-IR spectra confirmed the presence of characteristic functional groups and interlayer anions. Only Cu2+ which has a d9 configuration was accountable for the bands identified in UV-VIS spectra, whereas both Mg and Al with their d0 electron configurations showed no absorptive bands in the UV-VIS spectra. During thermal treatment by TGA, typical weight loss of Cu-Mg/Al HTLcs with temperature elevation was observed. The SEM images clearly demonstrated that all the Cu-Mg/Al HTLcs retained their characteristically layered structure morphologies. The BET surface area measurements showed no trend, however the surface area decreased with an increase in the copper concentration in some cases. For the heterogeneous hydroxylation of phenol using H2O2 as an oxidant, several reaction parameters such as solvent systems, catalyst amount, temperature, substrate/oxidant ratio, time and solvent volume were investigated. The product stream, monitored by gas chromatography showed that catechol (CAT) and hydroquinone (HQ) were the main products. Non-catalytic (blank) experiments were investigated to determine whether the reactants and the internal standard contributes to the conversion of phenol without the use of a catalyst. All blank reactions showed very low phenol conversions which were less than 1%, whereas the Mg/Al HTs showed low phenol conversions as well. All the Cu-Mg/Al catalysts showed measurable phenol conversion with Cu-Mg/Al-51a giving the highest conversion of 29.9% and a 56 and 44% selectivity towards CAT and HQ, respectively. The Cu-Mg/Al-15b catalyst, which had the lowest copper concentration, showed the lowest phenol conversion of 8.3% with a 55 % CAT selectivity and 45% HQ selectivity. In general, the phenol conversion increased with an increase in copper concentration. This reinforced the hypothesis that copper was the active centre in this reaction, since no measurable conversion was observed with Mg/Al HTs.

Rh/Ni wet-impregnated Ia3d mesostructured aluminosilicate and r-GO catalysts for hydrodeoxygenation of phenoxybenzene

2017 ◽  
Vol 41 (16) ◽  
pp. 7893-7907 ◽  
Author(s):  
Sudhakar Pichaikaran ◽  
Arumugam Pandurangan
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Structural Properties ◽  
Bet Surface Area ◽  
Xps Analysis ◽  
Icp Oes ◽  
Reduced Graphene ◽  
Ft Ir

Rh/Ni bimetallic supported bifunctional 3D porous aluminosilicate and Rh/Ni supported reduced graphene oxide (r-GO) catalysts were synthesised and their structural properties evaluated by XRD, BET-surface area, FT-IR, NH3-TPD, H2-TPR, ICP-OES, HRTEM-EDAX and XPS analysis.

scholarly journals Copper-doped Hydroxyapatite for Removal of Arsenic(V) from Aqueous System

2017 ◽  
Vol 9 (4) ◽  
pp. 383-402 ◽  
Author(s):  
S. A. Jahan ◽  
M. Y. A. Mollah ◽  
S. Ahmed ◽  
M. A. B. H. Susan
Keyword(s):  
Surface Area ◽  
Particle Size Analysis ◽  
Aqueous System ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Size Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Removal Of Arsenic

In this work, pure and copper-doped hydroxyapatite (various wt% of Cu) were synthesized by wet chemical precipitation method using eggshells as source of calcium. The efficiency of the prepared materials for removal of arsenic(V) from aqueous system has been investigated. Pure and Cu(II)-doped HAP were calcined at different temperatures ranging from 100-600 °C. The synthesized HAPs were characterized by Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscpic Analysis (EDS), particle size analysis based on dynamic light scattering measurements, and Brunauer–Emmett–Teller (BET) surface area analysis. FT-IR spectra and XRD patterns of synthesized HAPs confirmed the formation of single HAP phase. XRD patterns showed decrease in crystallite size for Cu-HAP compared to pristine HAP. BET surface area of Cu-HAP calcined at 300 °C increased to 153.39 m2g-1 from 66.80 m2g-1 for pure HAP. Finally, the synthesized HAPs were applied to remove As(V) from aqueous system. As(V) removal efficiency for Cu-HAP was two-fold higher than that of pure HAP. Adsorption behaviors were analyzed for As(V) adsorption on thermally treated pure and Cu-HAP using Langmuir, Freundlich, and Temkin adsorption isotherms. Finally, the prospect of Cu(II)-doped HAP for treatment of waste water containing heavy metals has been discussed.

scholarly journals A Comparative Study on The Adsorption Behavior of Congo Red on to ZnAl and ZnCr Layered Double Hydroxides

2020 ◽  
Vol 9 (2) ◽  
pp. 108-116
Author(s):  
Tarmizi Taher ◽  
◽  
Nyanyu Ummu Hani ◽  
Neza Rahayu Palapa ◽  
Risfidian Mohadi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Surface Area ◽  
Adsorption Kinetics ◽  
Layered Double Hydroxides ◽  
Congo Red ◽  
Adsorption Process ◽  
Bet Surface Area ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Double Hydroxides

In this work, two synthetic layered double hydroxides (LDH) consists of Zn2+ as M2+ cation with different M3+ cation, i.e., Al3+ and Cr3+ were used as an adsorbent for Congo Red removal aqueous solution. Both Zn-Al and Zn-Cr LDH were characterized by X-ray diffraction, FT-IR, and BET surface area analyzer. The effect of contact time, initial dye concentration, and temperature were evaluated in a batch technique in order to investigate the characteristic of Congo Red adsorption onto both adsorbents. The experimental data were assessed according to the parameter of adsorption kinetics, isotherm, and thermodynamics. The results of LDH characterization showed that Zn-Al LDH has a higher interlayer distance than Zn-Cr LDH, although Zn-Cr LDH has a higher surface area. The FT-IR analysis indicated the interlayer space of both Zn-Cr and Zn-Al LDH was dominated by CO32- as the interlayer anion species. The adsorption kinetics study of Congo Red on both LDH revealed that the adsorption process followed the pseudo-second-order model. For the adsorption isotherm, the experimental data fit well with the Freundlich model rather than the Langmuir model. The thermodynamic study indicated that the adsorption process that occurred on both adsorbents was spontaneous with exothermic nature.

scholarly journals Probing Internalization Effects and Biocompatibility of Ultrasmall Zirconium Metal-Organic Frameworks UiO-66 NP in U251 Glioblastoma Cancer Cells

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 867 ◽  
Author(s):  
Cataldo Arcuri ◽  
Lorenzo Monarca ◽  
Francesco Ragonese ◽  
Carmen Mecca ◽  
Stefano Bruscoli ◽  
...  
Keyword(s):  
Acridine Orange ◽  
Surface Area ◽  
Bet Surface Area ◽  
Spectroscopy Analysis ◽  
Cancer Cell Growth ◽  
Electron Microscopies ◽  
Vis Spectroscopy ◽  
Internalization Process ◽  
Metal Organic ◽  
Average Size

The synthesis of ultrasmall UiO-66 nanoparticles (NPs) with an average size of 25 nm, determined by X-ray powder diffraction and electron microscopies analysis, is reported. The NPs were stabilized in water by dialyzing the NP from the DMF used for the synthesis. DLS measurements confirmed the presence of particles of 100 nm, which are spherical aggregates of smaller particles of 20–30 nm size. The NP have a BET surface area of 700 m2/g with an external surface area of 300 m2/g. UiO-66_N (UiO-66 nanoparticles) were loaded with acridine orange as fluorescent probe. UV-vis spectroscopy analysis revealed no acridine loss after 48 h of agitation in simulated body fluid. The biocompatibility of UiO-66_N was evaluated in human glioblastoma (GBM) cell line U251, the most malignant (IV grade of WHO classification) among brain tumors. In U251 cells, UiO-66_N are inert since they do not alter the cell cycle, the viability, migration properties, and the expression of kinases involved in cancer cell growth. The internalization process was evident after a few hours of incubation. After 24 h, UiO-66_N@Acr (UiO-66_N loaded with acridine orange) were detectable around the nuclei of the cells. These data suggest that small UiO-66 are biocompatible NP and could represent a potential carrier for drug delivery in glioblastoma therapies.

scholarly journals Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
Titanium Silicate ◽  
Ft Ir ◽  
Synthesized Materials ◽  
Visible Light Photocatalytic

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

scholarly journals Spectrophotometric Determination of Trace Concentrations of Copper in Waters Using the Chromogenic Reagent 4-Amino-3-Mercapto-6-[2-(2-Thienyl)Vinyl]-1,2,4-Triazin-5(4H)-One: Synthesis, Characterization, and Analytical Applications

2020 ◽  
Vol 10 (11) ◽  
pp. 3895 ◽  
Author(s):  
Salman. S. Alharthi ◽  
Hamed. M. Al-Saidi
Keyword(s):  
Chemical Structure ◽  
Copper Concentration ◽  
Certified Reference Materials ◽  
Tap Water ◽  
Molar Absorptivity ◽  
Icp Oes ◽  
Chromogenic Reagent ◽  
Ft Ir ◽  
Trace Concentrations

A simple, selective, and inexpensive spectrophotometric method is described in the present study for estimation of trace concentrations of Cu2+ in water based on its reaction with chromogenic reagent namely 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one (AMT). The reaction between copper(II) ions and AMT reagent gives [Cu(L)(NO3)(H2O)2]•H2O complex, where L represents AMT molecule with NH group. The formed complex exhibits a sharp, and well-defined peak at λmax = 434 nm with a molar absorptivity (ε) of 1.90 × 104 L mol−1 cm−1, and Sandell’s factor of 0.003 μg mL−2. Absorbance of the [Cu(L)(NO3)(H2O)2]•H2O follows Beer’s law over a 0.7–25 μg mL−1 range with a detection limit of 0.011 μg mL−1. Validation of the submitted method was established by estimating Cu2+ in certified reference materials and actual sea and tap water samples. The results are compared with data obtained from copper concentration measurements using ICP-OES. The chemical structure of the Cu(II)-AMT complex was fully characterized by FT-IR, SEM, EDX, TGA, and ESR techniques.

Synthesis of Nano-Barium Titanate and Application for Strontium Adsorption from Aqueous Solution

2016 ◽  
Vol 1141 ◽  
pp. 190-195
Author(s):  
Hitesh Saravaia ◽  
Hariom Gupta ◽  
Vaibhav Kulshreshtha
Keyword(s):  
Barium Titanate ◽  
Surface Area ◽  
Active Surface ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Ft Ir ◽  
Tetragonal Batio ◽  
Thermal Stability Of

Barium Titanate (BaTiO3) nanostructures are synthesized by the molten salt-hydroxide reaction. The crystalline phase and chemical structure of the synthesized material are analyzed using powder x-ray diffraction (XRD) and FT-IR techniques, revealing the tetragonal BaTiO3 crystalline structure. Morphology and thermal stability of the material are characterized using TEM and TG-DTG analysis. BET surface area analysis shows significant active surface available for adsorption and its surface area value is found to be 14.8427 m2 g-1. The maximum adsorption of strontium metal is found to be 56.3 for the 1.2 g L-1 BaTiO3 adsorbent dose which reveals a remarkable separation property of the BaTiO3.

V and F Codoped TiO2-SiO2 Composite Films for Enhanced Photocatalytic Activity

2014 ◽  
Vol 955-959 ◽  
pp. 2384-2387
Author(s):  
Ling Xiao Guan ◽  
Yao Yao
Keyword(s):  
Photocatalytic Activity ◽  
Composite Film ◽  
Surface Area ◽  
Composite Films ◽  
Bet Surface Area ◽  
Methyl Green ◽  
Simple Process ◽  
Vis Spectroscopy ◽  
Excellent Photocatalytic Activity ◽  
Photocatalytic Activities

A simple process was developed for preparation of highly photoactive V and F codoped TiO2-SiO2 composite film. The as-prepared specimens were characterized using Brunauer–Emmett–Teller (BET) surface area, photoluminescence (PL) spectra, and UV–Vis spectroscopy. The BET results revealed that the surface area of the modified TiO2 sample was 413 m2 g-1, while pure TiO2 103 m2 g-1. The PL results showed that the recombination rate of the photo-generated electrons and holes was effectively prohibited via the multi-modification. The photocatalytic activities of the films were evaluated by degradation of methyl green (MG) dye. Compared with pure TiO2 film, the multi-modified TiO2 film exhibited excellent photocatalytic activity and clearly responsive to the visible light. Keywords: V and F codoping; TiO2-SiO2 composite film; Photocatalytic activity

Copper Oxide Nanoparticles as a Mild and Efficient Catalyst for N-Arylation of Imidazole and Aniline with Boronic Acids at Room Temperature

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1177-1182 ◽  
Author(s):  
Ashim Thakur ◽  
Raju Borah ◽  
Prasanta Raul ◽  
Abhijit Mahanta ◽  
Andrey Shchukarev ◽  
...  
Keyword(s):  
Surface Area ◽  
Room Temperature ◽  
Copper Oxide Nanoparticles ◽  
Particle Size Analysis ◽  
Significant Loss ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Oxide Nanoparticles ◽  
Efficient Catalyst ◽  
Ft Ir

The present work describes the excellent catalytic activity of copper(II) oxide nanoparticles (NPs) towards N-arylation of aniline and imidazole at room temperature. The copper(II)oxide NPs were synthesized by a thermal refluxing technique and characterized by FT-IR spectroscopy; powder XRD, SEM, EDX, TEM, TGA, XPS, BET surface area analysis, and particle size analysis. The size of the NPs was found to be around 12 nm having a surface area of 164.180 m2 g–1.The catalytic system was also found to be recyclable and could be reused in subsequent catalytic runs without a significant loss of activity.

Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 31-44 ◽  
Author(s):  
G. A. Ikhtiyarova ◽  
A. S. Özcan ◽  
Ö. Gök ◽  
A. Özcan
Keyword(s):  
Surface Area ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Thermal Analysis Techniques

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.

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