scholarly journals Synthesis and Characterization of Magnetic Xerogel Monolith as an Adsorbent for As(V) Removal from Groundwater

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 386
Author(s):  
Sasirot Khamkure ◽  
Sofía Esperanza Garrido-Hoyos ◽  
Prócoro Gamero-Melo ◽  
Audberto Reyes-Rosas
Keyword(s):  
Sol Gel ◽  
Freundlich Isotherm ◽  
Good Alternative ◽  
Epidemiological Studies ◽  
Point Of Zero Charge ◽  
Molar Ratio ◽  
Batch Adsorption ◽  
Arsenic Adsorption ◽  
Alkaline Catalyst ◽  
X Ray

Arsenic contamination of groundwater is still a global problem due to the toxicity at low dose on human health confirmed by epidemiological studies. Magnetic xerogel monoliths (MXs) were synthesized by the sol-gel polymerization using resorcinol, formaldehyde, alkaline catalyst and magnetite. The varying molar ratios of magnetite and resorcinol (M/R) in the gel were evaluated for As(V) removal from groundwater. The surface chemistry, structure and morphology of MXs related to arsenic adsorption were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and point of zero charge. Batch adsorption experiments were carried out to investigate the effects of Fe contents, initial pH and adsorbent dose on As(V) removal performance. The MXs with molar ratio of M/R at 0.15 gave the maximum As(V) adsorption capacity and removal with values of 62.8 µg/g and 86.7%, respectively. The adsorption data were well described by the Elovich equation of the kinetic model and the Freundlich isotherm. The thermodynamic studies demonstrated that the adsorption process was endothermic and spontaneous in nature. MXs showed to be a good alternative for As(V) removal from groundwater and achieving the efficient desorption, and thus fulfilled the Mexican standard for drinking water.

scholarly journals Prediction of the pH effect on arsenic (V) removal by varying catalyst of magnetic xerogel monoliths based on FREN model

2020 ◽  
Vol 20 (7) ◽  
pp. 2747-2761
Author(s):  
Sasirot Khamkure ◽  
Chidentree Treesatayapun ◽  
Sofía Esperanza Garrido-Hoyos ◽  
Prócoro Gamero-Melo ◽  
Audberto Reyes-Rosas
Keyword(s):  
Arsenic Removal ◽  
Ph Effect ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Point Of Zero Charge ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Alkaline Catalyst ◽  
X Ray ◽  
Application Range

Abstract Magnetic xerogels monoliths (MCs) were simultaneously prepared and formed by the cross-linking polymerization of resorcinol and formaldehyde using the alkaline catalyst and magnetite. The varying of molar ratio of resorcinol and catalyst (R/C) was studied and characterized by isoelectric point (IEP), point of zero charge (pHpzc), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), N2 adsorption and Fourier transform infrared spectroscopy (FTIR). The result of XRD and EDX confirmed the presence of magnetite into the gel at 1.19% with low molar ratio of magnetite and resorcinol ratio at 0.01. The surface morphology and textural properties of MCs affect directly with SBET, total pore volume and volume of mesopore increase when molar of R/C increases. The behavior of arsenic (As(V)) adsorption by using MCs, was studied in groundwater into the ranges of pH from 2.0 to 7.0. MC50 shows the maximum As(V) uptake and removal were 72 μg/g and 73.5% at pH 5, respectively, while MC100 gave the best performance within the application range of pH both of acidic and neutral region. Furthermore, the prediction technique based on an adaptive fuzzy rules emulated network was utilized for evaluation of the arsenic removal performance.

Study on Preparation and Photocatalytic Performance of Co-Doped TiO2 with Cu and Ce

2011 ◽  
Vol 399-401 ◽  
pp. 722-726 ◽  
Author(s):  
Jiang Ping Zhao ◽  
Xiao Ni Yang ◽  
Hao Zhang
Keyword(s):  
Photocatalytic Performance ◽  
Sol Gel ◽  
Test Chamber ◽  
Raw Material ◽  
Nano Particles ◽  
Molar Ratio ◽  
X Ray ◽  
Co Doping ◽  
Photocatalytic Activities ◽  
Environmental Test

In this paper, Cu-Ce/TiO2nano-particles, whose molar ratio account for 2%,2.5%,3%,3.5% and 4% respectively, were synthesized by sol-gel method, using Ti(C4H9O)4as the raw material, And the photocatalytic activities of the prepared samples were investigated by degrading formaldehyde gas under pure visible light through simulating indoor environment in the environmental test chamber. Moreover, X-Ray Powder Diffraction (XRD) and Ultraviolet-visible spectrophotometer were applied to analyze the crystallite size and optical properties of the samples. It is indicated that the sample of 2.5% performs best in the test. Besides, photocatalytic mechanism of co-doping of Cu-Ce was discussed.

scholarly journals Titanium Dioxide Coatings Doubly-Doped with Ca and Ag Ions as Corrosion Resistant, Biocompatible, and Bioactive Materials for Medical Applications

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 169
Author(s):  
Barbara Burnat ◽  
Patrycja Olejarz ◽  
Damian Batory ◽  
Michal Cichomski ◽  
Marta Kaminska ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Sol Gel ◽  
Immersion Test ◽  
Dip Coating ◽  
Biological Properties ◽  
Biological Evaluation ◽  
Molar Ratio ◽  
Bioactive Materials ◽  
Corrosion Resistant ◽  
X Ray

The aim of this study was to develop a multifunctional biomedical coating that is highly corrosion resistant, biocompatible, and reveals the bioactive properties. For that purpose, titanium dioxide coatings doubly-doped with Ca and Ag ions were deposited by dip-coating onto M30NW biomedical steel. The influence of different ratios of Ca and Ag dopants on morphology, surface structure, corrosion resistance, bioactivity, wettability, and biological properties of TiO2-based sol-gel coatings was studied and discussed. Comprehensive measurements were performed including atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray reflectivity (XRR), corrosion tests, immersion test, contact angle, as well as biological evaluation. The obtained results confirmed that anatase-based coatings containing Ca and Ag ions, independently of their molar ratio in the coating, are anticorrosive, hydrophilic, and bioactive. The results of the biological evaluation indicated that investigated coatings are biocompatible and do not reduce the proliferation ability of the osteoblasts cells.

scholarly journals ZnFe2O4-TiO2Nanoparticles within Mesoporous MCM-41

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Aidong Tang ◽  
Yuehua Deng ◽  
Jiao Jin ◽  
Huaming Yang
Keyword(s):  
Sol Gel ◽  
Rutile Phase ◽  
Band Gap Energy ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Agglomeration Of Nanoparticles ◽  
Adsorption Desorption ◽  
Mcm 41

A novel nanocomposite ZnFe2O4-TiO2/MCM-41 (ZTM) was synthesized by a sol-gel method and characterized through X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2adsorption-desorption, Raman spectroscopy, and ultraviolet visible (UV-vis) spectrophotometry. The results confirmed the incorporation of ZnFe2O4-TiO2nanoparticles inside the pores of the mesoporous MCM-41 host without destroying its integrity. ZnFe2O4nanoparticles can inhibit the transformation of anatase into rutile phase of TiO2. Incorporation of ZnFe2O4-TiO2within MCM-41 avoided the agglomeration of nanoparticles and reduced the band gap energy of TiO2to enhance its visible light photocatalytic activity. UV-vis absorption edges of ZTM nanocomposites redshifted with the increase of Zn/Ti molar ratio. The nanocomposite approach could be a potential choice for enhancing the photoactivity of TiO2, indicating an interesting application in the photodegradation and photoelectric fields.

scholarly journals Lead-Free BNT–BT0.08/CoFe2O4 Core–Shell Nanostructures with Potential Multifunctional Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 672
Author(s):  
Marin Cernea ◽  
Roxana Radu ◽  
Harvey Amorín ◽  
Simona Gabriela Greculeasa ◽  
Bogdan Stefan Vasile ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
Transmission Electron Microscopy Data ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Two Phase ◽  
X Ray ◽  
Shell Nanostructures

Herein we report on novel multiferroic core–shell nanostructures of cobalt ferrite (CoFe2O4)–bismuth, sodium titanate doped with barium titanate (BNT–BT0.08), prepared by a two–step wet chemical procedure, using the sol–gel technique. The fraction of CoFe2O4 was varied from 1:0.5 to 1:1.5 = BNT–BT0.08/CoFe2O4 (molar ratio). X–ray diffraction confirmed the presence of both the spinel CoFe2O4 and the perovskite Bi0.5Na0.5TiO3 phases. Scanning electron microscopy analysis indicated that the diameter of the core–shell nanoparticles was between 15 and 40 nm. Transmission electron microscopy data showed two–phase composite nanostructures consisting of a BNT–BT0.08 core surrounded by a CoFe2O4 shell with an average thickness of 4–7 nm. Cole-Cole plots reveal the presence of grains and grain boundary effects in the BNT–BT0.08/CoFe2O4 composite. Moreover, the values of the dc conductivity were found to increase with the amount of CoFe2O4 semiconductive phase. Both X-ray photoelectron spectroscopy (XPS) and Mössbauer measurements have shown no change in the valence of the Fe3+, Co2+, Bi3+ and Ti4+ cations. This study provides a detailed insight into the magnetoelectric coupling of the multiferroic BNT–BT0.08/CoFe2O4 core–shell composite potentially suitable for magnetoelectric applications.

The Effect of Stabiliser’s Molarity to the Growth of ZnO Nanorods

2011 ◽  
Vol 312-315 ◽  
pp. 99-103 ◽  
Author(s):  
Zuraida Khusaimi ◽  
Mohamad Hafiz Mamat ◽  
Mohd Zainizan Sahdan ◽  
Norbani Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Sol Gel ◽  
Zno Nanorods ◽  
Structural Features ◽  
Zinc Nitrate ◽  
Molar Ratio ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Chemical ◽  
Gel Preparation

A wet chemical approach, originating from sol-gel preparation, was adopted with the intention to develop a low-temperature benign method of preparation. ZnO nanorods are successfully grown in an aqueous medium. The precursor, zinc nitrate hexahydrate (Zn(NO3)2.6H2O), is stabilized by hexamethylene tetraamine (HMTA). The effect of changing the molarity of HMTA to the structural orientation of ZnO nanorods is investigated. X-ray diffraction of the synthesized ZnO shows hexagonal zincite structure. The structural features of the nanocrystalline ZnO were studied by SEM. Structural features, surface morphology and differences in lattice orientation are seemingly influenced by varying the Zn2+: HMTA molar ratio. The formation of ZnO nanorods with blunt and sharp tips is found to be significantly affected by this ratio.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Morphology and Phase Composition of Sol-Gel Derived Aluminum Borate Nanowhiskers

2015 ◽  
Vol 659 ◽  
pp. 121-126 ◽  
Author(s):  
Pat Sooksaen
Keyword(s):  
Fourier Transform ◽  
Phase Composition ◽  
Sol Gel ◽  
Molar Ratio ◽  
Aluminum Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
Sol Gel Synthesis ◽  
Scanning Electron

Aluminium borate nanowhiskers with varying aspect ratio were synthesized via sol–gel synthesis. The morphology of aluminum borate (Al4B2O9 and Al18B4O33) nanowhiskers could be controlled by varying the aluminum to boron (Al:B) molar ratio in the sol–gel derived precursors. Sintering temperatures (850 and 1100°C) and sintering times (4 and 32 hours) also affected the phase composition and size of the nanowhiskers. Citric acid was also added in the sol–gel derived precursors as a surface stabilizer for obtaining uniform finely dispersed nanostructures. Fine nanowhiskers were obtained by the calcination at 850°C, whereas higher temperature of 1100°C led to thicker and longer nanowhiskers and became rod-like crystals. The morphology and phase composition were investigated by field emission scanning electron microscope and X-ray diffraction. Chemical bond vibrations in the synthesized nanowhiskers were investigated by Fourier-transform infrared spectroscopy.

scholarly journals Synthesis of Ca-Doped Three-Dimensionally Ordered Macroporous Catalysts for Transesterification

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Tanat Chokpanyarat ◽  
Vittaya Punsuvon ◽  
Supakit Achiwawanich
Keyword(s):  
Reaction Time ◽  
Catalyst Concentration ◽  
Sol Gel ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hierarchical Porous ◽  
Ordered Macroporous

The novel three-dimensionally ordered macroporous (3DOM) CaO/SiO2, 3DOM CaO/Al2O3, and 3DOM Ca12Al14O32Cl2 catalysts for biodiesel transesterification were prepared by sol-gel method. The 3DOM catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The hierarchical porous structure was achieved; however, only 3DOM CaO/Al2O3 and 3DOM Ca12Al14O32Cl2 catalysts were used for transesterification due to high amount of active CaO. Various parameters such as methanol to oil molar ratio, catalyst concentration, reaction time, and their influence on the biodiesel production were studied. The result showed that 99.0% RPO conversion was achieved using the 3DOM Ca12Al14O33Cl2 as a catalyst under the optimal condition of 12 : 1 methanol to oil molar ratio and 6 wt.% catalyst with reaction time of 3 hours at 65°C.

N-Doped Cu11O2 (VO4)6 Photocatalyst Prepared by Sol-Gel Method

2011 ◽  
Vol 393-395 ◽  
pp. 1287-1290
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Qi Xing
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Photodegradation Rate ◽  
Triclinic Phase ◽  
Synthesized Materials

The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.

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