Extraordinary Stability of Structural and Electronic Properties of Tin Oxide Nanoparticles Formed by Soft Chemistry

Powders of tin dioxide (SnO2) have been prepared by two different modifications of wet chemical synthesis, i.e. (i) by conventional hydrolysis of tin chloride dissolved in aqueous ammonia solution and (ii) by precipitation from tin chloride dissolved in aqueous hydrazine monohydrate (N2H4*H2O) solution. The prepared gels were dried and then annealed at different temperatures varied from 300 to 700 oC in order to form nanocrystals. Structure and optical properties of the samples were investigated by using X-ray diffraction, transmission electron microscopy, thermoprogrammable hydrogen reduction, low temperature nitrogen adsorption method, photoluminescence, infra-red absorption, Raman spectroscopy, and X-ray photoelectron spectroscopy. The samples prepared by hydrazine-based method are characterized by surface area about 127-188 m2/g with high sintering resistance. The optical spectroscopy data revealed pure crystallinity and high defect concentration for the samples prepared by hydrazine-based method. The experimental results are discussed in view of different states of chemisorbed oxygen on SnO2 nanocrystal surfaces, which determine electronic and optical properties of the prepared samples.

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Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽

10.3390/cryst11020124 ◽

2021 ◽

Vol 11 (2) ◽

pp. 124

Author(s):

Srihasam Saiganesh ◽

Thyagarajan Krishnan ◽

Golla Narasimha ◽

Hesham S. Almoallim ◽

Sulaiman Ali Alhari ◽

...

Keyword(s):

Electron Microscopy ◽

Optical Properties ◽

Rare Earth ◽

Nickel Oxide ◽

Photoelectron Spectroscopy ◽

Metal Oxide Nanoparticles ◽

Oxide Nanoparticles ◽

Nio Nanoparticles ◽

X Ray ◽

Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

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Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽

10.3390/coatings11080937 ◽

2021 ◽

Vol 11 (8) ◽

pp. 937

Author(s):

Yingying Hu ◽

Md Rasadujjaman ◽

Yanrong Wang ◽

Jing Zhang ◽

Jiang Yan ◽

...

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Photoelectron Spectroscopy ◽

Crystal Size ◽

Silicon Substrates ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Flow Rates ◽

X Ray ◽

N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

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Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Nanomaterials ◽

10.3390/nano11061519 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1519

Author(s):

Jong Gyeong Kim ◽

Sunghoon Han ◽

Chanho Pak

Keyword(s):

Phosphoric Acid ◽

Photoelectron Spectroscopy ◽

Structural Changes ◽

Electronic States ◽

Nitrogen Adsorption ◽

Reduction Reaction ◽

Phosphorus Doping ◽

X Ray ◽

Precious Metal Catalysts ◽

Adsorption Desorption

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

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Study of the Effect of TiO2 Layer on the Adsorption and Photocatalytic Activity of TiO2-MoS2 Heterostructures under Visible-Infrared Light

International Journal of Photoenergy ◽

10.1155/2020/8740825 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

N. Cruz-González ◽

O. Calzadilla ◽

J. Roque ◽

F. Chalé-Lara ◽

J. K. Olarte ◽

...

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Nitrogen Adsorption ◽

High Photocatalytic Activity ◽

Infrared Light ◽

Polluted Water ◽

Light Spectrum ◽

X Ray

In the last decade, the urgent need to environmental protection has promoted the development of new materials with potential applications to remediate air and polluted water. In this work, the effect of the TiO2 thin layer over MoS2 material in photocatalytic activity is reported. We prepared different heterostructures, using a combination of electrospinning, solvothermal, and spin-coating techniques. The properties of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and X-ray photoelectron spectroscopy (XPS). The adsorption and photocatalytic activity were evaluated by discoloration of rhodamine B solution. The TiO2-MoS2/TiO2 heterostructure presented three optical absorption edges at 1.3 eV, 2.28 eV, and 3.23 eV. The high adsorption capacity of MoS2 was eliminated with the addition of TiO2 thin film. The samples show high photocatalytic activity in the visible-IR light spectrum.

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Preparation of Visible-Light-Responsive TiO2-xNx Photocatalyst by a Very Simple Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.3188 ◽

2011 ◽

Vol 383-390 ◽

pp. 3188-3191

Author(s):

Han Jie Huang ◽

Wen Long She ◽

Ling Wen Yang ◽

Hai Peng Huang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Diffuse Reflection ◽

Ammonia Solution ◽

Reflection Spectra ◽

X Ray Diffraction ◽

Simple Method ◽

X Ray ◽

Light Excitation

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

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Preparation and characterization of self-cleaning cotton fabric loaded with self-dispersive and reactive biphasic TiO2

10.21203/rs.3.rs-202290/v1 ◽

2021 ◽

Author(s):

Kuang Wang ◽

Jiayi Chen ◽

Jialong Tian ◽

Dawei Gao ◽

Xiaolei Song ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Cotton Fabrics ◽

Ammonia Solution ◽

X Ray ◽

Washing Fastness ◽

Fastness Property ◽

Structure Dispersion ◽

Ft Ir ◽

Self Cleaning

Abstract In this article, amino functionalized TiO2 (TiO2/KH550) was obtained in a mild reaction between 3-aminopropyltriethoxysilane and TiO2 with the aid of concentrated ammonia solution. 4-(4,6-dichloro-1,3,5-triazine-2-yl) amino) sodium benzenesulfonate (SAT) was synthesized and characterized by 1H NMR and fourier transform infrared spectroscopy (FT-IR). Self-dispersive and reactive TiO2 (TiO2/KH550/SAT) was prepared by nucleophile substitution reaction between TiO2/KH550 and SAT. Finally, cotton fabrics loaded with different amounts of TiO2/KH550/SAT were achieved by pad-dry-cure method. The chemical structure, dispersion and thermal performance of TiO2, TiO2/KH550 and TiO2/KH550/SAT were investigated by FT-IR, zeta potential and thermogravimetric analysis (TG). The crystalline phase, morphology, chemical composition and optical absorption property of cotton fabrics were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Moreover, the anti-ultraviolet, self-cleaning and washing fastness properties of cotton fabrics were investigated. It has been found that TiO2/KH550/SAT demonstrated excellent dispersion stability in aqueous even after standing for a month. Cotton fabrics loaded with TiO2/KH550/SAT possessed adorable anti-ultraviolet performance, highly efficient and durable self-cleaning activity as well as appreciable washing fastness property. The mechanism and possible reactions for the preparation of self-cleaning cotton fabrics loaded with TiO2/KH550/SAT were proposed.

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Studies of Effects of Calcination Temperature on the Crystallinity and Optical Properties of Ag-Doped ZnO Nanocomposites

Journal of Composites Science ◽

10.3390/jcs3010018 ◽

2019 ◽

Vol 3 (1) ◽

pp. 18 ◽

Cited By ~ 7

Author(s):

Md. Molla ◽

Mai Furukawa ◽

Ikki Tateishi ◽

Hideyuki Katsumata ◽

Satoshi Kaneco

Keyword(s):

Optical Properties ◽

Calcination Temperature ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Band Edge ◽

High Yield ◽

Band Edge Emission ◽

X Ray ◽

Calcination Temperatures ◽

Doped Zno

Ag-doped ZnO nanocomposites are successfully synthesized at different calcination temperatures and times through a simple, effective, high-yield and low-cost mechanochemical combustion technique. Effects of calcination temperature on the crystallinity and optical properties of Ag/ZnO nanocomposites have been studied by X-ray diffraction (XRD), UV−visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL) and X-ray photoelectron spectroscopy (XPS). The XRD patterns of the synthesized Ag/ZnO exhibit a well-crystalline wurtzite ZnO crystal structure. The grain size of Ag/ZnO nanocomposites is found to be 19 and 46 nm at calcination temperatures of 400 °C and 700 °C, respectively. The maximum absorption in the UV region is obtained for Ag/ZnO nanocomposites synthesized at a calcination temperature of 500 °C for 3 h. The peak position of blue emissions is almost the same for the nanocomposites obtained at 300–700 °C calcination temperatures. The usual band edge emission in the UV is not obtained at 330 nm excitation. Band edge and blue band emissions are observed for the use of low excitation energy at 335–345 nm.

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Metal-Organic Framework MIL-101: Synthesis and Photocatalytic Degradation of Remazol Black B Dye

Journal of Nanomaterials ◽

10.1155/2019/6061275 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Pham Dinh Du ◽

Huynh Thi Minh Thanh ◽

Thuy Chau To ◽

Ho Sy Thang ◽

Mai Xuan Tinh ◽

...

Keyword(s):

Photocatalytic Degradation ◽

Photoelectron Spectroscopy ◽

Metal Organic Framework ◽

Nitrogen Adsorption ◽

X Ray ◽

Remazol Black B ◽

Metal Organic ◽

Degradation Reaction ◽

Remazol Black ◽

Organic Framework

In the present paper, the synthesis of metal-organic framework MIL-101 and its application in the photocatalytic degradation of Remazol Black B (RBB) dye have been demonstrated. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption isotherms at 77 K. It was found that MIL-101 synthesized under optimal conditions exhibited high crystallinity and specific surface area (3360 m2·g-1). The obtained MIL-101 possessed high stability in water for 14 days and several solvents (benzene, ethanol, and water at boiling temperature). Its catalytic activities were evaluated by measuring the degradation of RBB in an aqueous solution under UV radiation. The findings show that MIL-101 was a heterogeneous photocatalyst in the degradation reaction of RBB. The mechanism of photocatalysis was considered to be achieved by the electron transfer from photoexcited organic ligands to metallic clusters in MIL-101. The kinetics of photocatalytic degradation reaction were analyzed by using the initial rate method and Langmuir-Hinshelwood model. The MIL-101 photocatalyst exhibited excellent catalytic recyclability and stability and can be a potential catalyst for the treatment of organic pollutants in aqueous solutions.

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Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽

10.3390/ma12111771 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1771 ◽

Cited By ~ 2

Author(s):

Stefan Neatu ◽

Mihaela M. Trandafir ◽

Adelina Stănoiu ◽

Ovidiu G. Florea ◽

Cristian E. Simion ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Catalytic Combustion ◽

Mixed Oxides ◽

Sol Gel ◽

Nitrogen Adsorption ◽

X Ray Diffraction ◽

X Ray ◽

Temperature Programmed ◽

Catalytic Combustion Of Methane ◽

Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

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Beta-Cyclodextrin-triggered fabrication of broccoli-like ZnO nanoaggregates with enhanced photocatalytic capability

Functional Materials Letters ◽

10.1142/s1793604720510042 ◽

2020 ◽

Vol 13 (02) ◽

pp. 2051004

Author(s):

Jinyan Xiong ◽

Wei Li ◽

Kai Zhao ◽

Weijie Li ◽

Gang Cheng

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Separation Efficiency ◽

Nitrogen Adsorption ◽

Electrochemical Measurement ◽

X Ray ◽

Recombination Efficiency ◽

Beta Cyclodextrin ◽

Composition And Structure ◽

Pollution Removal

Nanocrystallite aggregates have great potential in semiconductor-based photocatalysis toward environmental pollution removal. In this work, we reported the fabrication of broccoli-like zinc oxide nanoaggregates in the presence of beta-cyclodextrin in ethylene glycol-H2O medium. The composition and structure of the as-obtained ZnO nanoaggregates were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. It was observed that the beta-cyclodextrin played an important role in the fabrication of such broccoli-like structure. A plausible formation mechanism was discussed on the basis of the controllable experiments. The photocatalytic performance of the products was studied through the photodegradation of rhodamine B under simulated sunlight irradiation. Compared to the spherical ZnO nanoaggregates and ZnO broken spheres, the broccoli-like ZnO exhibited superior photocatalytic efficiency. Based on the photocurrent and electrochemical measurement results, the higher separation efficiency of the photogenerated carriers and lower recombination efficiency of the photoinduced electron–hole pairs over the broccoli-like ZnO nanoaggregates contributed to their remarkable photocatalytic activity.

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