Editor’s Choice – Catalytic and Photothermo-catalytic Applications of TiO2-CoOx Composites

Author(s):Roberto FiorenzaMarcello CondorelliLuisa D’UrsoGiuseppe CompagniniMarianna BellarditaLeonardo Palmisano and Salvatore Scirè*

Volume 1, Issue 1, 2020

Page: [3 – 15]

Pages: 13

DOI: 10.2174/2665976X01666200219113505

Abstract

Background: The necessity to have green and sustainable industrial processes has promoted new technologies for air and water purification together with the research of new energy sources. In this contest, the TiO2-based photocatalysis can be considered a promising route for both environmental applications and hydrogen production through water splitting.

Objective: In this work, we have investigated the photocatalytic performance of TiO2-CoOx composites on both photooxidation and photoreduction reactions. Specifically, we have compared the performance of the composites in the thermo-catalytic, photo-catalytic and photothermal-catalytic oxidation of ethanol chosen as model volatile organic compound (VOC) and in the photocatalytic hydrogen production by simulated solar light from aqueous solution of ethanol.

Methods: The samples were prepared with a simple impregnation method, and were characterized by Scanning Electron (SEM) and Transmission Electron (TEM) microscopies, X-ray powder diffraction (XRD), N2 adsorption-desorption measurements, Temperature Programmed Reduction in hydrogen (H2- TPR) and X-ray Photoelectron (XPS), Raman, UV-Vis Diffuse Reflectance (UV-Vis DRS) and Photoluminescence (PL) spectroscopies. The catalytic and photocatalytic activity were carried out on pyrex reactors irradiated with a solar lamp and analyzing the reactions products through gas chromatography.

Results: The presence and the amount of cobalt oxide were found crucial in determining the performance of the TiO2-based composites for both the catalytic and photocatalytic processes. In particular, the addition of 1 weight percent of CoOx led to the best performance in the photocatalytic processes, whereas a higher amount was beneficial in the thermo-catalytic tests. The multi-catalytic approach based on the synergistic effect of photocatalysis and thermocatalysis in the presence of the TiO2-1%CoOx sample allowed the temperature necessary to obtain 50% ethanol conversion and 50% yield in CO2 to be reduced by 40°C and 50°C, respectively. The same sample was also the best catalyst for photocatalytic solar H2 production.

Conclusion: The presence of small amounts of cobalt oxide leads to an efficient composite with TiO2 facilitating the space charge separation and increasing the lifetime of the generated photoholes and electrons. The wide versatility of TiO2-CoOx catalysts both for photooxidation and photoreduction reactions motivates to further exploit the use of these systems in real solar-driven photocatalysis. Read now: https://bit.ly/3dGdsJ5

Editor’s Choice – Simultaneous Photocatalytic Abatement of NO and SO2: Influence of the TiO2 Nature and Mechanistic Insights

Author(s):María D. Hernández-AlonsoSilvia Suárez Fernando FresnoJuan M. Coronado* and Benigno Sánchez*

Volume 2, Issue 2, 2021

Published on: 03 March, 2021

Page: [130 – 139]

Pages: 10

DOI: 10.2174/2665976X02666210303124330

Abstract

Background: TiO2 is currently being incorporated into several construction materials, such as cement and asphalt because this photocatalyst can act as a passive system to reduce the concentration of typical urban pollutants like NOx and SO2 under solar illumination.

Objective: In order to get further insights on the possible influence of the interaction between common pollutants, the present work investigates the mechanism of NOx photo-oxidation in the presence of SO2 traces over TiO2 samples of different textural and morphological characteristics.

Methods: The performance for the photo-oxidation of NOx and SO2 in a dry air stream over TiO2 samples, both commercial and lab-prepared by hydrothermal and thermal methods, was evaluated by means of FTIR analyses of the gas phase. These materials were characterized by XRD, N2 adsorption isotherms, and DR UV-vis spectroscopy. Mechanistic studies were performed by in situ DRIFT under UV irradiation.

Results: Photocatalytic tests showed a very efficient removal of the two selected pollutants using most of the TiO2 samples. In the case of SO2, elimination of these molecules is due not only to photocatalytic oxidation but also to a significant extent, to adsorption. Although in shorter periods, no byproducts are generated, following irradiation for several hours, the production of NO2 progressively increases and reaches 100 % selectivity over some photocatalyst. In situ DRIFTS analyses show the evolution of the surface composition and reveal the formation of the different types of surface nitrates with different symmetry. Under these operating conditions, a minor amount of sulfates are also formed.

Conclusion: The presence of a low concentration of SO2 does not appear to be detrimental for NO removal. NO2 formation is delayed on the TiO2 samples with high specific surface area, which also tend to be more active. The spectroscopic results confirm the involvement of surface hydroxyls in the formation of adsorbed nitrate species. Read now: https://bit.ly/3QwTpep

Editor’s Choice – Degradation of the O-phenylphenol Fungicide in Water by Unconventional CeO2-WO3 Photocatalysts

Author(s):Roberto FiorenzaStefano Andrea Balsamo and Salvatore Scirè*

Volume 2, Issue 3, 2021

Published on: 16 August, 2021

Page: [234 – 242]

Pages: 9

DOI: 10.2174/2665976X02666210816113433

Abstract

Background: Water pollution due to emerging contaminants such as pesticides, pharmaceutics and/or plasticizers, is a serious environmental problem strictly connected to the safety of human and ecosystem life. For this reason, the development of high-performing (photo)catalysts for water purification is crucial.

Objective: In recent years, the synergistic effects in Advanced Oxidation Processes (AOPs) can perform better strategies to remove recalcitrant contaminants from water. In this context, the (photo) catalytic activity of CeO2-WO3 materials for the degradation of the orto-phenylphenol fungicide comparing the photocatalytic, the Fenton and the photo-Fenton-like processes, has been examined.

Methods: The samples were synthetized through deposition-precipitation mediated with the hexamethylenetetramine (HMTA) surfactant. The chemico-physical properties of the materials were examined by Raman, UV-Vis Diffuse Reflectance (Uv-vis DRS) and X-Ray photoelectron (XPS) spectroscopies, N2 adsorption-desorption measurements and transmission electron microscopy (TEM). The (photo)catalytic measurements were made through a home-made photoreactor irradiated by a solar lamp. The degradation of the fungicide was measured by UV-vis spectroscopy.

Results: An efficient heterojunction was formed between the CeO2 and the WO3 oxides, which provided a good degradation percentage of the pesticide (65%) employing the solar photo-Fenton-like reaction that was the best performing process among the three investigated AOPs. The addition of WO3 on CeO2 facilitated the ionic exchange between the Ce and the W ions, boosting the redox properties of cerium oxide.

Conclusion: The strong interaction between CeO2 and WO3 and the peculiar properties of this unconventional composite pave the way to its use as a promising material for water depollution. Read now: https://bit.ly/3ppJuLQ

Become a Reviewer | Journal of Photocatalysis

 

Journal of Photocatalysis” would publish high quality research papers, reviews, and short communications focused on photocatalysis from many different scientific areas including Chemistry, Chemical Engineering, Materials Science, Materials Engineering, Environmental Engineering, Nanotechnology and Green Chemistry.

Journal of Photocatalysis” would accept novel papers in the following fields:

  • Preparation and characterization of new photocatalysts.
  • Photocatalytic elimination of environmental pollutants in liquid or gas phase.
  • Self-cleaning materials.
  • Thin films.
  • Photocatalytic syntheses of valuable products.
  • Photocatalytic hydrogen generation and CO2 reduction.
  • Kinetics and mechanistic aspects of photocatalytic reactions.
  • Combination of photocatalysis with other technologies, such as membrane technologies and photoelectrocatalysis.
  • Engineering aspects of photocatalytic processes.
  • Homogeneous photocatalysis.
  • Theory, modelling and computational aspects regarding the mechanisms of activation of photocatalysis.

The Journal Journal of Photocatalysis is interested in appointing active Reviewer on the Journal’s Board. If you are working in the related field as of the journal and are interested in becoming an Reviewer, please send us your CV and a list of publications. If, however, the scope of the journal is not directly related to your field, you can recommend suitable colleagues for the same, and, if possible, send their CV along with their list of publications. Mention in the subject line, the field of interest and send your CV at: hermain@benthamscience.net and CC: faizan@benthamscience.net

 

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Become an Editorial Board Member (EBM) | Journal of Photocatalysis

 

Journal of Photocatalysis” would publish high quality research papers, reviews, and short communications focused on photocatalysis from many different scientific areas including Chemistry, Chemical Engineering, Materials Science, Materials Engineering, Environmental Engineering, Nanotechnology and Green Chemistry.

Journal of Photocatalysis” would accept novel papers in the following fields:

  • Preparation and characterization of new photocatalysts.
  • Photocatalytic elimination of environmental pollutants in liquid or gas phase.
  • Self-cleaning materials.
  • Thin films.
  • Photocatalytic syntheses of valuable products.
  • Photocatalytic hydrogen generation and CO2 reduction.
  • Kinetics and mechanistic aspects of photocatalytic reactions.
  • Combination of photocatalysis with other technologies, such as membrane technologies and photoelectrocatalysis.
  • Engineering aspects of photocatalytic processes.
  • Homogeneous photocatalysis.
  • Theory, modelling and computational aspects regarding the mechanisms of activation of photocatalysis.

 

The Journal Journal of Photocatalysis is interested in appointing active Editorial Board Member  on the Journal’s Board. If you are working in the related field as of the journal and are interested in becoming an Editorial Board Member, please send us your CV and a list of publications. If, however, the scope of the journal is not directly related to your field, you can recommend suitable colleagues for the same, and, if possible, send their CV along with their list of publications. Mention in the subject line, the field of interest and send your CV at: hermain@benthamscience.net and CC: faizan@benthamscience.net

 

Wordpress

Call for Papers | Journal of Photocatalysis

AIMS & SCOPE

Journal of Photocatalysis” would publish high quality research papers, reviews, and short communications focused on photocatalysis from many different scientific areas including Chemistry, Chemical Engineering, Materials Science, Materials Engineering, Environmental Engineering, Nanotechnology and Green Chemistry.

“Journal of Photocatalysis” would accept novel papers in the following fields:

  • Preparation and characterization of new photocatalysts.
  • Photocatalytic elimination of environmental pollutants in liquid or gas phase.
  • Self-cleaning materials.
  • Thin films.
  • Photocatalytic syntheses of valuable products.
  • Photocatalytic hydrogen generation and CO2 reduction.
  • Kinetics and mechanistic aspects of photocatalytic reactions.
  • Combination of photocatalysis with other technologies, such as membrane technologies and photoelectrocatalysis.
  • Engineering aspects of photocatalytic processes.
  • Homogeneous photocatalysis.
  • Theory, modelling and computational aspects regarding the mechanisms of activation of photocatalysis.

To submit your paper, email at: hermain@benthamscience.net and CC: faizan@benthamscience.net

 

photocat-flyer.jpg

Open Access Articles | Treatment of Methylene Blue and Methyl Orange Dyes in Wastewater by Grafted Titania Pillared Clay Membranes

Author(s): Nalini Neethu, Tanushree Choudhury*.

 

 

 

Abstract:

Background: Amphoteric membranes such as Titania Pillared Clay (TiPILC) membranes exhibit different charges at different pH ranges, subsequently show efficient separation for cationic and anionic organic pollutants in wastewater based on solution pH. The structural properties of such membranes determine their permeability and selectivity to a large extent. The present work is initiated to explore the possibility of enhancing the surface area of TiPILC membranes by grafting with 3- aminopropyltriethoxysilane.

Method: Grafted TiPILC membranes were fabricated by colloidal sol- gel route followed by dip coating, drying and sintering the membranes at 300oC. X-ray diffraction (XRD) spectra of the pillared photocatalyst membranes show the presence of only anatase phase, which exhibits better photocatalytic activity. Fourier Transform Infrared (FT-IR) spectra reveal the formation of delaminated TiPILC material. The specific surface area of TiPILC membrane obtained at pH3.5 is 183m2/g.

Results: Literature survey of 47 papers was carried out for the work. 10 papers were based on Patents being dealt on degradation of organic dyes in wastewater by conventional methods, though reports of membrane technology are limited in literature. The rest 37 papers outlined the importance of widespread use of titania photocatalyst powder for degradation studies.

Conclusion: The membrane material thus developed is efficient in complete decolouration of both Methylene Blue and Methyl Orange dyes on account of the high surface charge and high surface area in just one cycle of filtration.

 

Read out more at: http://www.eurekaselect.com/166745

Most Cited Article : “Nanostructured Zinc Oxide for Water Treatment”

Nanoscience & Nanotechnology-Asia

Author(s): Sunandan Baruah, Samir K. Pal and Joydeep Dutta

nanoscience and nanotechnology2Abstract: Environmental pollution and industrialization on a global scale have drawn attention to the vital need for developing new hygienically friendly purification technologies. Existing wastewater treatment technologies demand high capital investment and operation & maintenance cost, and large area. Cost-effective treatment of pollutants requires the transformation of hazardous substances into benign forms and the subsequent development of effective risk management strategies from harmful effects of pollutants that are highly toxic, persistent, and difficult to treat. Application of nanotechnology that results in improved water treatment options might include removal of the finest contaminants from water (< 300 nm) and “smart materials” or “reactive surface coatings” with engineered specificity to a certain pollutant that destroy, transform or immobilize toxic compounds.

Read more here: http://benthamscience.com/journals/nanoscience-and-nanotechnology-asia/volume/2/issue/2/page/90/

Major Article Contributions by some of the Japanese Authors in Bentham Science Publishers Journal: Current Organic Chemistry

Article Title: Preparation of Novel Isotropic Pitch with High Softening Point and Solvent Solubility for Pitch-based Electrospun Carbon Nanofiber

Author(s): Byung-Jun Kim, Hyunsig Kil, Naoki Watanabe, Min-Hyun Seo, Bo-Hye Kim, Kap Seung Yang, Osamu Kato, Jin Miyawaki, Isao Mochida and Seong-Ho Yoon

Abstract:

The novel isotropic pitch that exhibits both high solvent solubility (100% soluble in THF) and a high softening point (over 200°C) was successfully synthesized by the bromination of 2-methylnaphthalene followed by dehydrobromination/polymerization and extraction in n-hexane to eliminate lighter constituents. The molecular structure of the pitch was relatively linear with flexible methylene cross-linkages between naphthalene molecules. During bromination, a reaction temperature of 180°C was necessary to induce bromine substitution of methyl hydrogen. Methylene cross-linkages were formed after the dehydrobromination reaction. The obtained pitch is a suitable precursor for electrospinning and meltspinning to prepare carbon nanofibers and carbon fibers, respectively.

For more details, visit: http://benthamscience.com/journal/abstracts.php?journalID=coc&articleID=111775

 

Article Title: Production and Purification of Functional Lipids Through Enzymatic and Microorganism-Mediated Processes

Author(s): Toshihiro Nagao, Yomi Watanabe, Hirofumi Nakano and Yuji Shimada

Abstract:

The most remarkable difference between a chemical reaction and a lipase reaction is the fact that lipase possesses several substrate specificities, in particular, fatty acid specificity on hydrolysis, esterification, or transesterification reaction of the ester bond. Several lipases act weakly on polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and arachidonic acid. Through fatty acid specificity of lipases, a DHA-rich oil (acylglycerols) has been industrially produced from tuna oil. Lipase specificity also facilitates purification of PUFAs, conjugated linoleic acid isomers, tocopherols, and sterol esters and production of triacylglycerol that is DHA– rich at the sn– 1(3) position. Microorganism-mediated processes using Aeromonas hydrophila N– 6 are effective for production of rare unsaturated fatty acids and rare unsaturated fatty alcohols from several vegetable oils. These lipids are rarely observed in natural oils. We also demonstrate that Acinetobacter sp. N– 476– 2 effectively converts functional arachidonic acid to functional arachidonyl alcohol, which can be used as a substrate for medicine.

For more details, visit: http://benthamscience.com/journal/abstracts.php?journalID=coc&articleID=108952

 

Article Title: Selective Photocatalytic Oxidation Of Benzyl Amine By O2 Into N-Benzylidenebenzylamine on Tio2 Using Visible Light

Author(s): Shinya Higashimoto, Yoshiaki Hatada, Ryo Ishikawa, Masashi Azuma, Yoshihisa Sakata and Hisayoshi Kobayashi

Abstract:

This paper deals with the photocatalytic oxidation of benzyl amine by O2 on TiO2 under visible light irradiation, and it was found that the benzyl amine is selectively converted into N-benzylidenebenzylamine with high conversion (>80 %). The origin of visible light response is not due to the band-gap transition of TiO2, but to the excitation of the charge transfer surface complex constructed by the interaction of benzyl amine with the TiO2 surface, as characterized by spectroscopic analysis such as UV-Vis, FT-IR and DFT calculations. Moreover, investigations of the role of the surface OH groups on TiO2, the electron-transfer from the surface complex as well as kinetic studies provided insight into the reaction mechanisms.
Article Title: Photocatalytic Reduction of Carbon Dioxide over Shape-Controlled Titanium(IV) Oxide Nanoparticles with Co-catalyst Loading
Author(s): Naoya Murakami, Daisuke Saruwatari, Toshiki Tsubota and Teruhisa Ohno
Abstract:

Photocatalytic reduction of carbon dioxide (CO2) was carried out using titanium(IV) oxide (TiO2). Methanol (CH3OH) was detected as the main product, and trace amounts of formic acid, carbon monoxide, methane, and hydrogen were also detected. The prepared decahedral-shaped anatase TiO2 with larger {011} and smaller {001} exposed crystal faces showed larger CH3OH generation than that of commercial anatase TiO2 powder, ST-01 (Ishihara Sangyo Co.). Photodeposition of silver and gold nanoparticles on the decahedral-shaped anatase TiO2 induced an increase in CH3OH production because the deposited metal particles work as reductive sites for multi-electron reduction of CO2.
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