Chemical properties, functionality, and morphology of taro flour modified by H2O2 oxidation and irradiation of UV light

Purpose – The aim of this paper is to evaluate the effects of ultraviolet (UV) light on the color, secondary metabolites and sensory acceptance of processed yerba-mate. Design/methodology/approach – Samples were exposed to UV light for 72 hours. The colorimetric coordinates (L*, a* and b*) were analyzed every 6 hours, while secondary metabolites and sensory acceptance were assessed at the beginning and at the end of the experiment. Methylxanthines and phenolic compounds were quantified by ultra performance liquid chromatography photodiode array detectors and vegetable pigments by UV/visible spectrophotometry. Findings – Decreases in methylxanthines, rutin and isomers of chlorogenic acids were found, along with an increase in isomers of dicaffeoylquinic acids. The product showed less sensory acceptance compared to the control. These results show that UV light treatment of yerba-mate accelerates the maturation process. Practical implications – UV light can be used in yerba-mate maturation with a reduction time and can ensure microbiological safety with small changes in its phytochemical profile. Originality/value – This paper is the first report of a novel strategy to investigate the yerba-mate maturation using UV light.

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Sethoxydim Response to Spray Carrier Chemical Properties and Environment

Weed Technology ◽

10.1017/s0890037x00039749 ◽

1994 ◽

Vol 8 (3) ◽

pp. 591-597 ◽

Cited By ~ 16

Author(s):

John D. Nalewaja ◽

Robert Matysiak ◽

Edward Szelezniak

Keyword(s):

Low Temperature ◽

Sodium Bicarbonate ◽

Leaf Surface ◽

Uv Light ◽

Chemical Properties ◽

Ammonium Hydroxide ◽

Ammonium Salts ◽

Uv Degradation ◽

Solution Ph ◽

Spray Solution

Experiments were conducted to determine the influence of spray carrier salts, UV light, and temperature on sethoxydim phytotoxicity to oat or yellow foxtail. Spray solution pH and ions present were both important to sethoxydim phytotoxicity to oat. Sodium and calcium salts were antagonistic to sethoxydim phytotoxicity only when the spray carrier pH exceeded 7. Ammonium salts and ammonium hydroxide were synergistic with sethoxydim, and the synergism was independent of spray solution pH. Ammonium sulfate, but not ammonium hydroxide, overcame sodium bicarbonate antagonism of sethoxydim. The antagonism of sethoxydim phytotoxicity by sodium bicarbonate was greatest in the presence of UV light and most pronounced when treated plants were exposed to mid-day sunlight. Sodium bicarbonate or low temperature may reduce the speed of sethoxydim absorption allowing for greater UV degradation of unabsorbed sethoxydim on the leaf surface.

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Synthesis and Characterization of N- Doped ZnO-γAl2O3 Nanoparticles for Photo-catalytic Application

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2019-0116 ◽

2019 ◽

Vol 18 (2) ◽

Author(s):

M. Mansouri ◽

A. Hosseinvand ◽

T. Kikhavani ◽

N. Setareshenas

Keyword(s):

Diffuse Reflectance Spectroscopy ◽

Uv Light ◽

Chemical Properties ◽

Catalyst Loading ◽

X Ray Diffraction ◽

Catalytic Application ◽

Photo Catalysis ◽

Doped Zno ◽

Physical And Chemical

Abstract In this study, photo-catalytic degradation of methyl orange (MO) azo dye was examined by undoped and Ce2O3/ CuO/ N doped ZnO nanoparticles stabilized on γAl2O3. Highest photo-catalytic activity was observed for the N-doped 10 wt. % ZnO-γAl2O3 sample. One of the optimal points with the complete MO decomposition was determined at an initial concentration of 8.25 ppm, pH 3.25, catalyst loading of 0.36 g/L and 12.56 W UV-light irradiation after 120 min. Physical and chemical properties of materials were investigated by X-ray diffraction analysis (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) and UV–visible diffuse reflectance spectroscopy (DRS) method. The experimental data were best fitted by a Langmuir-Hinshelwood approach photo-catalysis developed kinetic reaction rate in the form of $- r = 0.2797\, {I^{0.5}}\, {[Cat.]^{0.5}}\, \, [Dye]{\text{ }}/\, \, \, 1 + 0.1079\, {[Dye]_0}\, + \, 0.4086\, {I^{0.5}}\, {[Cat.]^{0.5}}$.

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Hydrothermal Synthesis of TiO2/SiO2 Hybrid Photocatalyst from Rice Husk Ash

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.352.281 ◽

2007 ◽

Vol 352 ◽

pp. 281-285 ◽

Cited By ~ 2

Author(s):

P. Sujaridworakun ◽

Supatra Jinawath ◽

W. Panpa ◽

Akira Nakajima ◽

Masahiro Yoshimura

Keyword(s):

Rice Husk ◽

Rice Husk Ash ◽

Uv Light ◽

Porous Silica ◽

Chemical Properties ◽

Nano Crystalline ◽

Ultraviolet Ray ◽

Physical And Chemical ◽

Hydrolysis Of ◽

Fine Tio2

Photocatalyst materials were prepared as a hybrid between TiO2 /SiO2 via low temperature hydrothermal method (150oC) without further heat treatment. Porous silica from rice husk ash was used as a support for fine TiO2 particles which acted as a photocatalyst when radiated with a UV light. TiO2-deposited SiO2 was successfully prepared through hydrolysis of TiOSO4 solution by controlling synthesis parameters such as pH ,concentration of TiOSO4, temperature and time under hydrothermal treatment. The obtained products were characterized for physical and chemical properties by means of XRD, XRF, BET and TEM . It was found that pH had an influence on the crystallization of TiO2, and under an appropriated pH, only anatase presented along with amorphous phase. High crystallinity of nano-crystalline anatase ( about 5 nm) deposited on silica surface was observed through TEM. Adsorption and photocatalytic performances of the prepared catalyst were evaluated in methylene blue aqueous solution in the dark and under ultraviolet ray irradiation, respectively. Due to the synergetic functions of adsorption by porous substrate and decomposition by TiO2 photocatalyst, an enhancing of photocatalytic activity for decomposition of organic pollutants in water under UV rays was obtained.

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Decolorization of crystal violet over TiO2 and TiO2 doped with zirconia photocatalysts

Hemijska industrija ◽

10.2298/hemind160521036v ◽

2017 ◽

Vol 71 (3) ◽

pp. 259-269 ◽

Cited By ~ 1

Author(s):

Marija Vasic ◽

Marjan Randjelovic ◽

Jelena Mitrovic ◽

Nikola Stojkovic ◽

Branko Matovic ◽

...

Keyword(s):

Crystal Violet ◽

Uv Light ◽

Sol Gel ◽

Chemical Properties ◽

Dye Decolorization ◽

Operational Parameters ◽

Physico Chemical ◽

Irradiation Treatment ◽

Catalytic Material ◽

Reaction Cycles

Titania based catalyst and TiO2 doped with zirconia were prepared by modified sol?gel method. The synthesized catalysts samples were characterized by BET, XRD, SEM and FTIR techniques. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolorization/decomposition under UV light irradiation. The effect of several operational parameters, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment and number of reaction cycles were also considered. The obtained results indicated faster dye decolorization with the increase of the catalyst amount and a decrease of initial CV concentrations. An influence of doping with zirconia on the physico-chemical properties of bare titania was studied. The doping procedure had affected photocatalytic properties of the final catalytic material, and had improved photocatalytic performances of doped catalyst on crystal violet decolorization/degradation in comparison to bare titania.

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Diameter- and Length-controlled Synthesis of Ultrathin ZnS Nanowires and Their Size-Dependent UV Absorption Properties, Photocatalytical Activities and Band-Edge Energy Levels

Nanomaterials ◽

10.3390/nano9020220 ◽

2019 ◽

Vol 9 (2) ◽

pp. 220 ◽

Cited By ~ 4

Author(s):

Guanjie Xing ◽

Xiaoli Liu ◽

Simeng Hao ◽

Xiaohong Li ◽

Louzhen Fan ◽

...

Keyword(s):

High Efficiency ◽

Uv Light ◽

Energy Levels ◽

Chemical Properties ◽

Continuous Extension ◽

Band Edge ◽

Selective Absorption ◽

Absorption Properties ◽

Size Dependent ◽

Degradation Of Dyes

Benefiting from their ultra-small diameters and highly structural anisotropies, ultrathin semiconductor nanowires (USNWs) are well-known for their fascinating physical/chemical properties, as well as their promising applications in various fields. However, until now, it remains a challenge to synthesize high-quality USNWs with well-controlled diameters and lengths, let alone the exploration of their size-dependent properties and applications. To solve such a challenge, we report herein a ligand-induced low-temperature precursor thermolysis route for the controlled preparation of ultrathin ZnS nanowires, which is based on the oriented assembly of the in-situ formed ZnS clusters/tiny particles. Optimized synthetic conditions allowed the synthesis of ZnS nanowires with a diameter down to 1.0 nm and a length approaching 330 nm. The as-prepared ultrathin ZnS nanowires were then intensively examined by morphological, spectroscopic and electrochemical analytical means to explore their size-dependent optical absorption properties, photocatalytic activities and band-edge energy levels, as well as their underlying growth mechanism. Notably, these USNWs, especially for the thinnest nanowires, were identified to possess an excellent performance in both the selective absorption of ultraviolet (UV) light and photocatalytic degradation of dyes, thus enabling them to serve as longpass ultraviolet filters and high-efficiency photocatalysts, respectively. For the ultrathin ZnS nanowires with a diameter of 1.0 nm, it was also interesting to observe that their exciton absorption peak positions were kept almost unchanged during the continuous extension of their lengths, which has not been reported previously.

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Structural and Photocatalytic Property of CaTiO3 Nanosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.979.169 ◽

2020 ◽

Vol 979 ◽

pp. 169-174 ◽

Cited By ~ 1

Author(s):

C. Karthikeyan ◽

M. Thamima ◽

S. Karuppuchamy

Keyword(s):

Dye Degradation ◽

Uv Light ◽

Chemical Properties ◽

Photocatalytic Property ◽

Advanced Characterization ◽

Morphological Studies ◽

Physico Chemical ◽

Raman Study ◽

Ft Ir ◽

Xrd Patterns

The nanostructured photocatalysts are the most promising materials for the degradation of toxic dyes. Particularly, CaTiO3 has been used in several applications including catalytic, optical, biological and electronic. In this present study, perovskite structured CaTiO3 nanomaterials have been synthesized by microwave irradiation method. The physico-chemical properties of the prepared CaTiO3 nanomaterials were studied by various advanced characterization techniques. The XRD patterns confirm the presence of perovskite structure of the prepared nanomaterials. FT-IR analysis confirms the presence of Ca-Ti-O vibrational bonds. Micro Raman study display the existence of O-Ca-Ti-O with B1g mode of vibrations. Morphological studies revealed the presence of truncated nanospheres. The dye degradation property of prepared CaTiO3 was investigated by Malachite green (MG) by UV-light.

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Novel Photocatalytic NH3 Synthesis by NO3− Reduction over CuAg/TiO2

ChemEngineering ◽

10.3390/chemengineering3020049 ◽

2019 ◽

Vol 3 (2) ◽

pp. 49 ◽

Cited By ~ 1

Author(s):

Ryota Kato ◽

Mai Furukawa ◽

Ikki Tateishi ◽

Hideyuki Katsumata ◽

Satoshi Kaneco

Keyword(s):

High Efficiency ◽

Ammonia Synthesis ◽

Uv Light ◽

Reaction System ◽

Chemical Properties ◽

Molar Ratio ◽

Optimum Conditions ◽

Nitrate Ions ◽

Hole Scavenger ◽

Loading Amount

The highly effective reaction system was investigated for the photocatalytic ammonia synthesis from the reduction of nitrate ions by using the semiconductor photocatalyst, Cu and Ag doped on TiO2 (CuAg/TiO2) at room temperature under UV light irradiation (max. 352 nm). In this study, CuAg/TiO2 gave the high efficiency and the selectivity for the ammonia synthesis by the photoreduction of nitrate in the presence of methanol as a hole scavenger. For the evaluation of the photocatalytic activity over CuAg/TiO2, various TiO2 samples, such as standard TiO2, Cu/TiO2, and Ag/TiO2, were evaluated in the same procedure. The chemical properties were investigated by XRD, TEM, XPS, PL, and DRS. We examined the optimum conditions for the experimental factors and the important issues, including the effect of the molar ratio of Cu and Ag onto TiO2, the optimization of the CuAg amount loaded on TiO2, the influence of the loading amount of the catalyst on the reduction of nitrate ions, the exploration of the optimum hole scavenger, and the reusability of the optimum photocatalyst. The very efficient conversion of nitrate ions (95%) and the highest selectivity (86%) were achieved in the reaction with the optimum conditions. Here, we reported the process that nitrate ions can efficiently be reduced, and ammonia can be selectively synthesized over CuAg/TiO2.

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Synthesis and Characterization of Active Carbon-Titanium Dioxide Composite

Asian Journal of Chemistry ◽

10.14233/ajchem.2019.21906 ◽

2019 ◽

Vol 31 (5) ◽

pp. 1176-1180

Author(s):

Farah S. Daabool ◽

Falah H. Hussein

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Activated Carbon ◽

Uv Light ◽

Titanium Dioxide Nanoparticles ◽

Chemical Activation ◽

Sol Gel ◽

Chemical Properties ◽

Growth Conditions ◽

Activation Technique

Activated carbon was synthesized from Iraqi date palm seeds by physical and chemical activation technique under optimized growth conditions that allow the production of long, well aligned, high-quality activated carbon. Titanium dioxide nanoparticles were prepared using a sol gel method. The activated carbon/TiO2 composites were prepared using simple evaporation and a drying process. The structural, morphological and chemical properties of the prepared activated carbon, TiO2 and activated carbon/TiO2 composite were investigated by X-ray diffraction, Fourier transformed infrared and scanning electron microscope. The photocatalytic activity of activated carbon/TiO2 composite with 10 % of activated carbon was studied and compared with TiO2. The UV light photocatalytic activity was also evaluated by the photocatalytic degradation of phenol in an aqueous solution.

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Synthesis and Application of 1-[(2-methyl-3-benzothiophene)]-2-[2-methyl-5-(1,3-dioxolane)-3-thienyl]perfluorocyclopentene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1078.94 ◽

2014 ◽

Vol 1078 ◽

pp. 94-97

Author(s):

Ying Long Fu ◽

Ling Yao Zhou ◽

Cong Bin Fan ◽

Shou Zhi Pu

Keyword(s):

Reduction Potential ◽

Uv Light ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Oxidation Reduction ◽

Oxidation Reduction Potential ◽

Reversible Cyclization ◽

Physical And Chemical ◽

Constant Refractive Index ◽

And Chemical Properties

A new unsymmetrical photochromic diarylethene 1-[(2-methyl-3-benzothiophene)]-2-[2-methyl-5-(1,3-dioxolane)-3-thienyl] perfluorocyclopentene (1o) has been synthesized. In the meantime, its photochromic, kinetics and fluorescence properties were investigated in detail. The results showed this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in solution [1]. The two isomers differ from each other not only in their absorption spectras, but also in many changes of various physical and chemical properties, such as dielectric constant, refractive index, as well as oxidation/reduction potential, etc [2]. Diarylethene 1 changed the color from colorless to pink upon irradiation with 297 nm UV light, in which absorption maxima were observed at 516 nm in acetonitrile.

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