Facile Biosynthesis and Antioxidant Property of Nanogold-Cellulose Fiber Composite

Direct synthesis of gold nanoparticles (AuNPs) on cellulose fiber has been successfully performed via facile green approach using lignin-containing unbleached kraft softwood pulp. The resulting AuNPs composited fibers showed apparent color change from pale yellow to purplish-dark brown by varying the amount of gold ions (Au3+) due to the surface plasmon resonance of nanogold. Further confirmation of AuNP formation on the fiber surface was conducted by UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). X-ray photoelectron spectroscopy (XPS) analysis revealed that gold nanoparticles formed on the fiber are well-defined pure metallic gold, indicating that Au3+ions are efficiently bioreduced into Au0and bind to the fiber surface. Antioxidant activity was evaluated by decomposition of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) in dark and light condition. As-prepared unbleached kraft fiber-AuNP composite showed significantly enhanced antioxidant activity and its DPPH scavenging rate reached about 86.05%.

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AQUEOUS-BASED FORMATION OF GOLD NANOPARTICLES ON SURFACE-MODIFIED COTTON TEXTILES

Journal of Molecular and Engineering Materials ◽

10.1142/s2251237312500013 ◽

2013 ◽

Vol 01 (01) ◽

pp. 1250001 ◽

Cited By ~ 3

Author(s):

HONGJUN LIU ◽

WEI-PENG GOH ◽

TYLER B. NORSTEN

Keyword(s):

Gold Nanoparticles ◽

Surface Treatment ◽

Photoelectron Spectroscopy ◽

Fiber Surface ◽

Vinyl Pyrrolidone ◽

Cotton Fibers ◽

Au Nps ◽

X Ray ◽

Cotton Textiles ◽

Surface Modified

A facile and environmental friendly route has been developed to synthesize gold nanoparticles (AuNPs) by using amine stabilizers and N-vinyl pyrrolidone (NVP) as the reductant in an aqueous medium. This synthetic concept can be applied to the formation of Au NPs on normal cotton fibers via in situ surface modification of the cotton fibers by (3-aminopropyl)triethoxysilane (ATS) followed by nanoparticle formation. This scheme produces red Au NP-dyed cotton textiles. Surface treatment of the cotton textiles by ATS was found to be crucial for the formation of nano- Au . X-ray photoelectron spectroscopy (XPS), diffused reflectance UV-visible spectroscopy (UV-vis) and energy dispersive X-ray (EDX) were used to investigate the fiber surfaces. The distribution of Au NPs as well as surface treatment agent on the fiber surface was located by time of flight secondary ion mass spectroscopy (TOF-SIMS).

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Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽

10.3390/separations8030025 ◽

2021 ◽

Vol 8 (3) ◽

pp. 25

Author(s):

Chukwuka Bethel Anucha ◽

Ilknur Altin ◽

Emin Bacaksız ◽

Tayfur Kucukomeroglu ◽

Masho Hilawie Belay ◽

...

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Sol Gel ◽

Pure Tio2 ◽

Component Part ◽

Energy Yield ◽

Mechanical Agitation ◽

X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

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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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Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes

Advances in Materials Science and Engineering ◽

10.1155/2016/3532817 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Huang Liu ◽

Yanhua Zhang ◽

Hongtao Yang ◽

Wei Xiao ◽

Lanlan Sun

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Filter Paper ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Cellulose Nanofibers ◽

Titania Nanotubes ◽

Tetrabutyl Titanate ◽

X Ray ◽

Porous Titania

Using the common natural cellulose substance (filter paper) and triblock copolymer (Pluronic P123) micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%.

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Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities

International Journal of Photoenergy ◽

10.1155/2012/915386 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Jiang Zhang ◽

Zheng-Hong Huang ◽

Yong Xu ◽

Feiyu Kang

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Oxygen Vacancies ◽

Diffuse Reflectance Spectroscopy ◽

Synergetic Effect ◽

X Ray Diffraction ◽

X Ray ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Photocatalytic Activities

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.

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Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

Canadian Journal of Chemistry ◽

10.1139/v11-028 ◽

2011 ◽

Vol 89 (7) ◽

pp. 845-853 ◽

Cited By ~ 9

Author(s):

Sadok Letaief ◽

Wendy Pell ◽

Christian Detellier

Keyword(s):

Carbon Monoxide ◽

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Fine Particles ◽

Raw Materials ◽

Carbon Monoxide Oxidation ◽

Functional Materials ◽

Metallic State ◽

Oxidation Reactions ◽

X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

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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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3D Modeling of Silver Doped ZrO2 Coupled Graphene-Based Mesoporous Silica Quaternary Nanocomposite for a Nonenzymatic Glucose Sensing Effects

Nanomaterials ◽

10.3390/nano12020193 ◽

2022 ◽

Vol 12 (2) ◽

pp. 193

Author(s):

Kamrun Nahar Fatema ◽

Chang-Sung Lim ◽

Yin Liu ◽

Kwang-Youn Cho ◽

Chong-Hun Jung ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Mesoporous Silica ◽

Photoelectron Spectroscopy ◽

Glucose Sensor ◽

Diffuse Reflectance Spectroscopy ◽

Active Material ◽

Glucose Sensing ◽

X Ray ◽

Transmission Electron

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10−3 mAcm−2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

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Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV-Irradiation

10.20944/preprints201809.0583.v1 ◽

2018 ◽

Author(s):

Irwing M. Ramírez-Sánchez ◽

Erick R. Bandala

Keyword(s):

Photocatalytic Activity ◽

Electron Microscope ◽

Uv Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Bet Surface Area ◽

Doped Tio2 ◽

X Ray ◽

Transmission Electron ◽

Iron Doped

Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (•OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide® TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.

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Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

Canadian Journal of Chemistry ◽

10.1139/v98-146 ◽

1998 ◽

Vol 76 (11) ◽

pp. 1707-1716 ◽

Cited By ~ 30

Author(s):

I Coulthard ◽

S Degen ◽

Y -J Zhu ◽

T K Sham

Keyword(s):

Gold Nanoparticles ◽

Porous Silicon ◽

Photoelectron Spectroscopy ◽

Gold Nanoclusters ◽

Gold Complex ◽

X Ray Diffraction ◽

Complex Ions ◽

X Ray ◽

Preparation Conditions ◽

P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

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