Solution combustion synthesis, characterization, photocatalytic activity and electrochemical studies of yttrium stabilized zirconia ( Zr0.72 Y0.28 O1.862 ) nanopowder.

2021 ◽  
Vol 06 ◽  
Author(s):  
Rajeshwari G ◽  
Chandrappa Gujjarahalli thimmanna
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Bet Surface Area ◽  
Cubic Phase ◽  
Oh Radicals ◽  
Electrochemical Studies ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Solution Combustion ◽  
X Ray

Background: In our work, we effectively synthesized Yttrium stabilized zirconia (YSZ) Zr0.72 Y0.28 O1.862 nanopowder by solution combustion method using yttrium nitrate (Y(NO3)3.6H2O), zirconyl nitrate (ZrO(NO3)2.XH2O) as oxidizers and ethylenediamine tetra acetic acid (EDTA) as a fuel. The as-synthesized nanopowder was characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Breauner Emmet Teller (BET) surface area, UV-Vis diffuse reflectance spectrum (UV-DRS) and photoluminescence (PL) technique. The phase formation of YSZ nanopowder was analysed by Powder X-ray diffraction (PXRD) revealed the formation of pure cubic phase of YSZ (Zr0.72 Y0.28 O1.862) nanopowder and the crystallite size of 15.4 nm was calculated by using Scherrer’s formula. Methods: The porous morphology of the product was observed by SEM images. The relatively larger surface area of 87.17 m2g–1 was measured by BET surface area. TEM analysis revealed uniform particle size distribution with average particle sizes varying in the range of 20-100 nm. The UV-Vis DRS spectrum was used to calculate the absorption wavelength (339 nm) and the corresponding band gap (3.72 eV) using Tauc plot. The photoluminescence spectrum of YSZ nanopowder showed an emission peak at 339 nm. Results: The photodegradation (decolourisation) of methylene blue (MB) dye was increased from 75-90% with increase in the concentration of YSZ photocatalyst from 100 mg to 400 mg due to availability of OH radicals in the presence of UV radiation. Conclusion : The electrochemical studies using cyclic voltammetry reveal a substantial increase in current density of YSZ electrode from 0.0001A to 0.0005A when compared with bare carbon electrode and the instantaneous rise in redox current for the YSZ electrodes from 0.0001A to 0.0005A with increasing scan rate from 10 mVs-1 to 90 mVs-1.

scholarly journals Synthesis and Characterisation of Mesoporous TiO2 Nanoparticles by Novel Surfactant Assisted Sol-gel Method for the Degradation of Organic Compounds

2018 ◽  
Vol 63 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Harish Phattepur ◽  
Gowrishankar Bychapur Siddaiah ◽  
Nagaraju Ganganagappa
Keyword(s):  
Electron Microscopy ◽  
Tio2 Nanoparticles ◽  
Surface Area ◽  
Sol Gel ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Tio2 Nps ◽  
Gel Method ◽  
X Ray ◽  
Surfactant Assisted

A sol-gel method was employed to synthesise pure titanium dioxide (TiO2) and surfactant assisted TiO2 nanoparticles (NPs). The effect of novel surfactant viz., Lauryl lactyl lactate on photocatalytic properties of TiO2 was studied. TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Diffuse Reflectance spectra (DRS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Thermo gravimetric analysis (TGA), and Brunauer – Emmet - Teller (BET) surface area. Anatase phase of TiO2 was confirmed by X-Ray diffraction pattern and the crystallite size was between 9–19 nm. Addition of surfactant improved the BET surface area, surface defects, while the agglomeration of particles was reduced. DRS results revealed that the addition of surfactant to TiO2 sol induced a red shift of the absorption edge which resulted in the reduction of band gap from 3.23 to 3.21 eV. These physicochemical properties of TiO2 NPs were correlated with photocatalytic degradation of phenol. About 92% of phenol degradation was observed for surfactant assisted TiO2 NPs (SA-TiO2). Salicylic acid and caffeine were also degraded using SA-TiO2 NPs.

Synthesis and Characterization of Zero-Valent Iron Nanoparticles

2015 ◽  
Vol 1112 ◽  
pp. 62-65 ◽  
Author(s):  
Eka Sri Yusmartini ◽  
Dedi Setiabudidaya ◽  
Ridwan ◽  
Marsi ◽  
Faizal
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Bet Surface Area ◽  
Material Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Process Characterization ◽  
Transmission Electron ◽  
Zero Valent Iron Nanoparticles

Nanoparticles, particles of size 10-9have a high potential as water, waste water and air pollution treatment. In this research, nanoscale iron particles were synthesized by reduction of Fe2SO47 H2O by NaBH4at low temperature to avoid oxidation during the process. Characterization of the particles based on particle size, material structure, surface morphology and the composition of forming element was done by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectometry (EDS), respectively. Surface area and magnetic character was measured by BET surface area and vibrating sample magnetometry (VSM), respectively. Morfological observation showed that structured core-shell of size < 44 nm and shell of size ~ 3 nm with saturated magnetization value ~ 132 emu g‾¹ has been formed.

Decontamination of Heavy Metals from Wastewater Effluent Using Polypyrrole/Polyvinylpyrrolidone Nanoparticles

2020 ◽  
Vol 1008 ◽  
pp. 15-20
Author(s):  
Sara E. Zayan ◽  
Ahmed Hassan El-Shazly ◽  
Marwa Farouk El-Kady
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Surface Area ◽  
Wastewater Effluent ◽  
Bet Surface Area ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polypyrrole Nanoparticles ◽  
Scanning Electron

Polypyrrole nanoparticles prepared in the presence and absence of polyvinylpyrrolidone (PPy/PVP) fine black powders have been synthesized as adsorbents for the removal of copper Cu (Ⅱ) and iron Fe (Ⅲ) ions from aqueous solution. PPy and PPy/PVP were chemically prepared by using ferric chloride as an oxidant, and distillate water as a solvent with and without polyvinylpyrrolidone as a surfactant. The prepared PPy and PPy/PVP adsorbents were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area, and Fourier Transform Infrared spectroscopy (FTIR). The results display BET surface area equals 7.88 and 21.93 for PPy and PPy/PVP, respectively. The data also shows that PPy/PVP acts as flawless adsorbent for the removal of copper and iron ions from aqueous solution with sequestration percentage of 90% and 83% in 2 hours respectively.

scholarly journals Facile Template In-Situ Fabrication of ZnCo2O4 Nanoparticles with Highly Photocatalytic Activities under Visible-Light Irradiation

2019 ◽  
Vol 14 (2) ◽  
pp. 404 ◽  
Author(s):  
Vu T. Tan ◽  
La The Vinh ◽  
Tran Ngoc Khiem ◽  
Huynh Dang Chinh
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Fabrication ◽  
Transmission Electron

High specific surface area ZnCo2O4 nanoparticles were prepared via a sacrificial template accelerated hydrolysis by using nanoparticles of ZnO with highly polar properties as a template. The obtained ZnCo2O4 nanoparticles were characterized by the method of scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurements, Transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The obtained nanoparticles were performed as a photocatalyst for the degradation of methylene blue in aqueous solution under visible irradiation. The photocatalytic degradation rate of methylene blue onto the synthesized ZnCo2O4 was higher than that of commercial ZnO and synthesized ZnO template. Copyright © 2019 BCREC Group. All rights reserved. 

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

scholarly journals Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Chemical Compositions ◽  
Ion Adsorption ◽  
X Ray ◽  
Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

scholarly journals Synthesis and Characterization of Co-Mo/γ-Alumina Catalyst from local Kaolin clay for Hydrodesulfurization of Iraqi Naphtha

2021 ◽  
Vol 11 (1) ◽  
pp. 84-106
Author(s):  
Nada Sadoon Ahmed zeki ◽  
Sattar Jalil Hussein ◽  
Khalifa K. Aoyed ◽  
Saad Kareem Ibrahim ◽  
Ibtissam K. Mehawee
Keyword(s):  
Surface Area ◽  
Sulfur Removal ◽  
Sulfuric Acid Concentration ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mo Catalyst ◽  
Pressure Time ◽  
Al2o3 Catalyst

This work deals with the hydrodesulfurization of three types of naphtha feedstocks; mixednaphtha (WN), heavy naphtha (HN) & light naphtha (LN) with a sulfur content of 1642.1,1334.9 & 709 ppm respectively, obtained from Missan refinery using prepared Co-Mo/γ-Al2O3catalyst. The Iraqi white kaolin was used as a starting material for the preparation of γ-Al2O3support, transferring kaolin to meta-kaolin was studied through calcination at differenttemperatures and durations, kaolin structure was investigated using X-Ray diffractiontechniques.High purity 94.83%. Crystalline γ-Al2O3 with a surface area of 129.91 m2/gm, pore volume0.9002 cm3/g was synthesized by extraction of Iraqi kaolin with H2SO4 at different acid to clayweight ratios, acid concentrations & leaching time. Ethanol was used as precipitating agent; theresultant gel was dried and calcined at 70OC, 10 hrs & 900 OC, 2 hrs respectively.The effects of different parameters on the average crystallinity and extraction % ofsynthesized γ-Al2O3 were studied like; acid: clay ratio, sulfuric acid concentration, leachingtime, leaching temperature & kaolin conversion to metakaolin. Characterization of prepared γ-Al2O3 & Co-Mo catalyst were achieved by X-ray diffraction, FTIR-spectra, texture properties& BET surface area, BJH N2 adsorption porosity, AFM, SEM, crush strength & XRF tests. Co-Mo/ γ-Al2O3 catalyst with final loading 5.702 wt% and 21.45 wt% of Co and Mo oxidesrespectively was prepared by impregnation methods.The activity of prepared Co-Mo/γ-Al2O3 catalyst after moulding to be tested forhydrodesulfurization (HDS) of naphtha feedstock W.N, H.N & L.N was performed using apilot hydrotreating unit at petroleum research & development centre, at different operatingconditions. Effects of temperature, LHSV, pressure, time & pore size distribution were studied,the best percentage of sulfur removal is increased with decreasing LHSV to 2 hr-1 as a generaltrend to be 89.71, 99.72, 99.20 % at 310oC for the whole naphtha, heavy naphtha and lightnaphtha feedstocks respectively, at 34 bar pressure and 200/200 cm3/cm3 H2/HC ratio.

scholarly journals Microwave-assisted preparation of ZnS and ZnSe nanocrystals with different morphologies for photodegradation process of organic dyes

2019 ◽  
Author(s):  
Katarzyna Matras-Postolek ◽  
A. Zaba ◽  
S. Sovinska ◽  
D. Bogdal
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Zinc Sulphide ◽  
Conventional Heating ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Zinc sulphide (ZnS) and zinc selenide (ZnSe) and manganese-doped and un-doped with different morphologies from 1D do 3D microflowers were successfully fabricated in only a few minutes by solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained  nanocrystals, additionally the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The photocatalytic activity of ZnSe, ZnS, ZnS:Mn and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO) and Rhodamine 6G (R6G), respectively. The results show that Mn doped NCs samples had higher coefficient of degradation of organic dyes under ultraviolet irradiation (UV).

The Influence of Introduction of Polyethylene Glycol on Synthesis of Bimodal Mesoporous γ-Al2O3

2013 ◽  
Vol 709 ◽  
pp. 89-92
Author(s):  
Xiang Li ◽  
Xin Mei Liu ◽  
Zi Feng Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
X Ray ◽  
Transmission Electron ◽  
Increasing Trend ◽  
Opposite Tendency

In the presence of polyethylene glycol (PEG2W),bimodal mesoporous γ-Al2O3 was successfully synthesized via hydrothermal method. The samples were respectively characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimeter (TG-DSC). Introduction of PEG2W can increase the relative crystallinity of AACH and γ-Al2O3. The BET surface area and pore volume of alumina shows an increasing trend with increasing of PEG2W content, while the pore size shows an opposite tendency. The PEG2W also plays an important role in inducing the formation of the nanorod-like alumina.

scholarly journals The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2261 ◽  
Author(s):  
Abdul Wafi ◽  
Erzsébet Szabó-Bárdos ◽  
Ottó Horváth ◽  
Mihály Pósfai ◽  
Éva Makó ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Surface Area ◽  
Photocatalytic Performance ◽  
Visible Region ◽  
Bet Surface Area ◽  
Doped Tio2 ◽  
X Ray ◽  
Nitrogen Doped ◽  
Visible Light Driven

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

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