scholarly journals Effect of Silver Modification on the Photoactivity of Titania Coatings with Different Pore Structures

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2240
Author(s):  
Borbála Tegze ◽  
Emőke Albert ◽  
Boglárka Dikó ◽  
Norbert Nagy ◽  
Adél Rácz ◽  
...  
Keyword(s):  
Functional Properties ◽  
Rutherford Backscattering Spectrometry ◽  
Silver Content ◽  
Operating Conditions ◽  
Blue Dye ◽  
Impregnation Method ◽  
X Ray ◽  
Pore Structures ◽  
Vis Spectroscopy ◽  
Self Cleaning

Nanostructured photoactive systems are promising for applications such as air and water purification, including self-cleaning coatings. In this study, mesoporous TiO2 sol-gel coatings with different pore structures were prepared and modified with silver by two methods: the “mixing” method by adding AgNO3 to the precursor sol, and the “impregnation” method by immersing the samples in AgNO3 solution (0.03 and 1 M) followed by heat treatment. Our aim was to investigate the effects that silver modification has on the functional properties (e.g., those that are important for self-cleaning coatings). Transmittance, band gap energy, refractive index, porosity and thickness values were determined from UV-Vis spectroscopy measurements. Silver content and structure of the silver modified samples were characterized by X-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, High-resolution transmission electron microscopy and Energy Dispersive X-ray Spectrometry elemental mapping measurements. Wettability properties, including photoinduced wettability conversion behavior were investigated by water contact angle measurements. Photoactivity was studied under both UV and visible light with rhodamine 6G and methylene blue dye molecules, at the liquid–solid and air–solid interfaces modeling the operating conditions of self-cleaning coatings. Samples made with “impregnation” method showed better functional properties, in spite of their significantly lower silver content. The pore structure influenced the Ag content achieved by the “impregnation” method, and consequently affected their photoactivity.

Property of Cu2O-CuO/ZSM-5 nanocomposite and degradation process of azo dye AO7 without sacrificial agent (H2O2)

2016 ◽  
Vol 73 (11) ◽  
pp. 2747-2753 ◽  
Author(s):  
Wusong Kong ◽  
Hongxia Qu ◽  
Peng Chen ◽  
Weihua Ma ◽  
Huifang Xie
Keyword(s):  
Catalytic Activity ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Surface Element ◽  
Impregnation Method ◽  
X Ray ◽  
Initial Ph ◽  
Sacrificial Agent

In this study, Cu2O-CuO/ZSM-5 nanocomposite was synthesized by the impregnation method, and its catalytic performance for the destruction of AO7 in aqueous solutions was investigated. The morphology, structure and surface element valence state of Cu2O-CuO/ZSM-5 were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The operating conditions on the degradation of AO7 by Cu2O-CuO/ZSM-5, such as initial pH values, concentration of AO7 and catalyst dosage were investigated and optimized. The results showed that the sample had good catalytic activity for destruction of AO7 in the absence of a sacrificial agent (e.g. H2O2): it could degrade 91% AO7 in 140 min at 25 °C and was not restricted by the initial pH of the AO7 aqueous solutions. Cu2O-CuO/ZSM-5 exhibited stable catalytic activity with little loss after three successive runs. The total organic carbon and chemical oxygen demand removal efficiencies increased rapidly to 69.36% and 67.3% after 120 min of treatment by Cu2O-CuO/ZSM-5, respectively.

Ultra-sonication enhanced green synthesis of silver nanoparticles using Barleria buxifolia leaf extract and its possible application

2021 ◽  
Author(s):  
Vanaraj sekar
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Leaf Extract ◽  
Cancer Cell Line ◽  
Xrd Analysis ◽  
Blue Dye ◽  
Multiple Use ◽  
Uniform Size ◽  
X Ray ◽  
Vis Spectroscopy

Abstract A simple and eco-friendly method for the green synthesis of silver nanoparticles (AgNPs) by ultrasound-assisted strategy using Barleria buxifolia leaf extract as a reducing and capping agent was established in this study. The obtained AgNPs were characterized. UV-vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM and TEM), Energy Dispersive X-Ray Analyzer (EDX), X-ray diffraction, dynamic light scattering (DLS) analysis showed that the obtained AgNPs were mono dispersed spheres with uniform size of 80 nm. UV-vis spectroscopy, FTIR, and XRD analysis indicated that the surface of the obtained AgNPs was covered with organic molecules in plant extracts. The results of ABTS assays showed that high antioxidant activity was seen in the obtained AgNPs. Green synthesized AgNPs showed potent antibacterial and anti-biofilm activity against tested pathogens. Cytotoxicity assay showed that the obtained AgNPs were significantly cytotoxic to cancer cell line (MCF-7). In addition, the AgNPs synthesized in this paper can also photo catalytically degrade methylene blue dye under visible light. The potent bioactivity exhibited by the green synthesized silver nanoparticles leads towards the multiple use as antioxidant, antibacterial, anti-biofilm, cytotoxic as well as photo catalytic agent.

Photocatalytic Comparative Study of TiO2, ZnO, Ag-G-ZnO and Ag-G-TiO2 Nanocomposite Films

2017 ◽  
Vol 751 ◽  
pp. 825-830 ◽  
Author(s):  
Phuri Kalnaowakul ◽  
Tonghathai Phairatana ◽  
Aphichart Rodchanarowan
Keyword(s):  
Colloidal Solution ◽  
Nanocomposite Films ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities ◽  
Xrd Patterns

In this study, the photocatalytic properties and morphology of TiO2, ZnO, Ag-graphene-zinc oxide (Ag-G-ZnO) and Ag-graphene-titanium dioxide (Ag-G-TiO2) nanocomposite were compared. The Ag-G-ZnO and Ag-G-TiO2 nanocomposite were successfully prepared by thermal decomposition of colloidal solution. These prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and photocatalytic activities. The results from XRD patterns show that Ag-G-TiO2 composites and the Ag-G-ZnO nanocomposites were in the form of fcc and hcp crystal structure, respectively. The SEM images show that at calcination of 500 °C for 3 h, the composite thin film of Ag-G-ZnO and Ag-G-TiO2 were homogenous. In the case of the photocatalytic experiments using methylene blue dye (MB) under UV irradiation, the order of the photocatalytic activities from high to low performances are Ag-G-ZnO, Ag-G-TiO2, ZnO and TiO2, respectively.

scholarly journals Visible Light-Driven Photocatalytic Activity and Kinetics of Fe-Doped TiO2 Prepared by a Three-Block Copolymer Templating Approach

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3105
Author(s):  
Antonietta Mancuso ◽  
Olga Sacco ◽  
Vincenzo Vaiano ◽  
Barbara Bonelli ◽  
Serena Esposito ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Operating Conditions ◽  
Soft Template ◽  
Quantitative Phase Analysis ◽  
Doped Tio2 ◽  
X Ray ◽  
Undoped Tio2 ◽  
Fe Content ◽  
Vis Spectroscopy

Fe-doped titania photocatalysts (with 1, 2.5, and 3.5 wt. % Fe nominal content), showing photocatalytic activity under visible light, were prepared by a soft-template assisted sol–gel approach in the presence of the triblock copolymer Pluronic P123. An undoped TiO2 photocatalyst was also prepared for comparison. The photocatalysts were characterized by means of X-ray powder Diffraction (XRPD), Quantitative Phase Analysis as obtained by Rietveld refinement, Diffuse Reflectance (DR) UV−Vis spectroscopy, N2 adsorption/desorption at −196 °C, electrophoretic mobility in water (ζ-potential), and X-ray photoelectron spectroscopy (XPS). The physico-chemical characterization showed that all the samples were 100% anatase phase and that iron was present both in the bulk and at the surface of the Fe-doped TiO2. Indeed, the band gap energy (Eg) decreases with the Fe content, with Tauc’s plot determined values ranging from 3.35 (undoped TiO2) to 2.70 eV (3.5 wt. % Fe). Notwithstanding the obtained Eg values, the photocatalytic activity results under visible light highlighted that the optimal Fe content was equal to 2.5 wt. % (Tauc’s plot determined Eg = 2.74 eV). With the optimized photocatalyst and in selected operating conditions, under visible light it was possible to achieve 90% AO7 discoloration together with a TOC removal of 40% after 180 min. The kinetic behavior of the photocatalyst was also analyzed. Moreover, the tests in the presence of three different scavengers revealed that the main reactive species are (positive) holes and superoxide species. Finally, the optimized photocatalyst was also able to degrade phenol under visible light.

scholarly journals Synthesis of CaxCu3-xTi4O12 Perovskite Materials and house-hold LED light mediated degradation of Rhodamine Blue dye

2021 ◽  
Author(s):  
Priyankamoni Saikia ◽  
Hemanga Jyoti Sarmah ◽  
Shahnaz Ahmed ◽  
Suman Lahkar ◽  
Jyoti Prakash Das ◽  
...  
Keyword(s):  
Defect Density ◽  
Dye Degradation ◽  
Degradation Process ◽  
Band Gap Energy ◽  
Blue Dye ◽  
X Ray ◽  
Led Light ◽  
Molar Ratios ◽  
Calcium Copper Titanate ◽  
Vis Spectroscopy

Abstract This report describes a comparative study of dye degradation under 20-watt LED light using the perovskite photocatalyst Calcium Copper Titanate (CCTO) and its compositions (CaxCu3−xTi4O12) (x = 1, 1.5 and 2), synthesized by changing molar ratios of Ca2+ and Cu2+ ions. The 99.74% degradation of Rhodamine Blue (RhB) with composition (x = 1) within 6 h is reflected its better photocatalytic activity than the parent CCTO and other compositions. The band gap energy of the materials 2.18 eV (CCTO), 1.93 eV (x = 1), 2.40 eV (x = 1.5), and 2.55 eV (x = 2) are analysed with UV-Vis spectroscopy. The presences of Ca, Cu, Ti and O in the synthesized photocatalysts are confirmed with Elemental X-ray Dispersive (EDX) analysis. The cubic phases in the polyhedral shape of the materials are detected in X-ray diffraction and Scanning Electron Microscopy (SEM). This report further observes the defect density concentrations of the materials with Photoluminescence Spectroscopy (PL) and provides the approximate explanation of their dye degradation performance as photocatalysts. The rate constants are found in a first order reaction trend; where the composition (x = 1) shows about 1.683×10− 2 min− 1. The mechanistic understanding of the degradation process is also revisited and rationalized with different scavengers for the process.

scholarly journals SINTESIS NANOPARTIKEL Ag/CoFe2O4 MENGGUNAKAN EKSTRAK DAUN BINAHONG (Anredera cordifolia (Ten) Steenis) DAN APLIKASINYA SEBAGAI FOTOKATALIS UNTUK MENDEGRADASI ZAT WARNA METHYLENE BLUE

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
David Tjiang ◽  
Henry F. Aritonang ◽  
Harry S. J. Koleangan
Keyword(s):  
Methylene Blue ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Contact Time ◽  
Leaf Extract ◽  
Blue Dye ◽  
Cofe2o4 Nanoparticles ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

ABSTRAKTelah dilakukan penelitian tentang kemampuan fotodegradasi zat warna sintetik Methylene Blue dengan menggunakan nanopartikel Ag/CoFe2O4 dengan variasi perbandingan mol AgNO3:(Co(NO3)2.6H2O): (Fe(NO3)3.9H2O)= 0,3:0,7:2 dan jumlah ekstrak daun binahong (Anredera cordifolia (Ten) Steenis) yang ditambahkan 10 mL. Material tersebut dikarakterisasi menggunakan X-Ray Diffractometry (XRD), Scanning Electron Microscope (SEM) dan spektroskopi UV-vis. Kemampuan fotodegradasi dilakukan melalui penentuan konsentrasi Methylene Blue (konsentrasi awal 5 ppm) yang tersisa setelah berinteraksi dengan nanopartikel Ag/CoFe2O4 yang disinari sinar UV-A selama 30, 60, 120 dan 150 menit. Penentuan konsentrasi dihitung berdasarkan absorbansi yang didapatkan dari hasil pembacaan uji Spektrofotometri UV-vis, lalu digunakan rumus menghitung persen degradasi. Hasil penelitian menunjukkan bahwa yang memiliki kemampuan fotodegradasi paling baik adalah nanopartikel Ag/CoFe2O4 (0,3 : 0,7 : 2) mol dengan waktu kontak 120 menit, yaitu dengan nilai persen degradasi sebesar 44,84 %. ABSTRACTA research on photodegradation ability Methylene Blue dye synthetic by using Ag/CoFe2O4 nanoparticles with a mole ratio variation AgNO3 : (Co(NO3)2.6H2O) : (Fe(NO3)3.9H2O)= 0,3:0,7:2 and the amount of binahong (Anredera cordifolia (Ten) Steenis) leaf extract added 10 mL. These materials were characterized using X-Ray Diffractometry (XRD), Scanning Electron Microscope (SEM) and UV-vis Spectroscopy. Ability photodegradation done by determining the concentration of Methylene Blue is residue after the interaction with Ag/CoFe2O4 nanoparticles with irradiated UV-A for 30, 60, 120 and 150 minutes. Determining the concentration is calculated based on the absorbance obtained from the results of the analysis of UV-vis Spectrophotometry and then used a formula calculating the percent degradation. The results showed that the ability is best photodegradation Ag/CoFe2O4 nanoparticles (0,3: 0,7: 2) moles with a contact time of 120 minutes with a degradation value of 44.84%.

scholarly journals Photocatalytic Hydrogen Production from Urine Using Sr-Doped TiO2 Photocatalyst with Subsequent Phosphorus Recovery via Struvite Crystallization

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1012
Author(s):  
Oranoot Sittipunsakda ◽  
Patiya Kemacheevakul ◽  
Navadol Laosiripojana ◽  
Surawut Chuangchote
Keyword(s):  
Hydrogen Production ◽  
Tio2 Nanoparticles ◽  
Human Urine ◽  
Environmental Problems ◽  
Phosphorus Recovery ◽  
Impregnation Method ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Struvite Crystallization

Currently, the discharge of wastewater and utilization of phosphorus (P) in human activities cause some environmental problems, such as high organic pollutants in aquatic environments which results in dirty water sources, and a shortage of phosphate rock reserves due to the high demand of P. Therefore, fuel energy and struvite crystallization from waste sources can be considered interesting alternatives. In this work, the modified catalyst for hydrogen production, along with solving environmental problems, was examined. The strontium (Sr) doped-titanium dioxide (TiO2) nanoparticles were synthesized by wetness impregnation method. The synthesized catalyst was characterized using UV-vis spectroscopy (UV-vis), photoluminescence (PL), X-ray diffraction (XRD), photoluminescence (PL), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). The Sr-doped TiO2 catalysts had been utilized as the photocatalyst for the hydrogen production from synthetic human urine (a representative of waste source). The doping content of Sr in TiO2 varied from 0.5, 1, 2, and 4%, and the photocatalytic performances were compared with pristine TiO2 nanoparticles. The results showed that 1% Sr-doped TiO2 had the highest photocatalytic activity for hydrogen production and decreased the amount of chemical oxygen demand (COD) in the synthetic human urine. Subsequently, P could be recovered from the treated human urine in the form of struvite.

scholarly journals Decolorization of Methylene Blue Dye Using ZnO/ZSM-5 Photocatalyst Under UV-LED Irradiation

2020 ◽  
Vol 16 (2) ◽  
pp. 81
Author(s):  
Lely Dwi Astuti ◽  
Yuly Kusumawati ◽  
Didik Prasetyoko ◽  
Wahyu Bambang Widayatno ◽  
Abdul Hamid
Keyword(s):  
Methylene Blue ◽  
Blue Dye ◽  
Impregnation Method ◽  
Methylene Blue Dye ◽  
X Ray ◽  
Uv Led ◽  
Activity Test ◽  
M 10 ◽  
Percent Removal ◽  
Led Irradiation

<span id="docs-internal-guid-710aacff-7fff-63c8-d621-c027e79f6f4f"><span><strong>ABSTRACT. </strong></span><span>The present research studied about decolorization of methylene blue dye using photocatalyst ZnO/ZSM-5 under UV-LED lamp. ZnO/ZSM-5 was synthesized using the impregnation method by adding two grams ZSM-5 to Zn solution 0.3 M 10 mL. Photocatalyst was characterized using X-ray diffractometer (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy-energy dispersive X-Ray (FESEM-EDX), and surface area analyzer (SAA). Analysis using XRD show addition characteristic peaks of ZnO at 2θ 31.60°, 34.21°, 36.08°, 47.35°, 56.50°, 62.73°, 67.83°, that indicates a successful impregnation process. The photocatalysis activity test was done on methylene blue dye 100 mg L-1. ZSM-5 and ZnO activities were tested under UV-LED irradiation and dark conditions. Data showed that percent removal of dye occurred on ZnO/ZSM-5 under 15 minutes irradiation is 78.32%.</span></span>

scholarly journals Understanding Pore Surface Modification of Sucrose-Modified Iron Oxide/Silica Mesoporous Composite for Degradation of Methylene Blue

2021 ◽  
Vol 16 (3) ◽  
pp. 459-471
Author(s):  
Yuvita Eka Pertiwi ◽  
Maria Ulfa ◽  
Teguh Endah Saraswati ◽  
Didik Prasetyoko ◽  
Wega Trisunaryanti
Keyword(s):  
Methylene Blue ◽  
Iron Oxide ◽  
Surface Area ◽  
Heterogeneous Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Impregnation Method ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Wide Range

Santa Barbara Amorphous (SBA-15) containing iron oxide with a sucrose-modified in a heterogeneous reaction for degradation methylene blue (MB) successful synthesized used hydrothermal, ultrasonication, and wet impregnation method. SBA-15 is mesoporous silica that can easily serve as external and internal surfaces making it suitable for a wide range of applications. The structure and morphology of materials were characterized using Surface Area Analyzer (SAA), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Transmission Electron Microscopy (TEM). Iron oxide impregnated as a maghemite phase has an average size of 12 nm and well distributed on the SBA-15. After modified with sucrose the materials remaining stable, which has a two-dimensional hexagonal (p6mm) structure, high specific surface area, and large pore volume (up to 1.82 cm3.g−1). The degradation of MB was evaluated under visible light irradiation using UV-Vis spectroscopy. Catalytic activity showed efficiencies of 52.9; 70.2; and 21.1% for SBA-15, Fe2O3/SBA-15, and sucrose-modified Fe2O3/SBA-15 respectively. Sucrose-modified Fe2O3/SBA-15 has the lowest efficiency, which probably occurs due to the presence of pore-blocking and the formation of micropores on the external pore. The modification with sucrose has the advantage of producing a high surface area even though there is a catalytic center due to partial decomposition which causes a decrease in the efficiency of degradation of MB. All materials provide a high micro surface area so that they can be further adapted and can be widely applied to many potential applications as both catalyst support and an adsorbent. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Nano Sized ZnO/MnO2/Gd2O3 Ternary Heterostructures for Enhanced Photocatalysis

2020 ◽  
Vol 5 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Shubha Pranesh ◽  
Jayalakshmi Nagaraju
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Visible Light ◽  
Effluent Treatment ◽  
Small Scale ◽  
Blue Dye ◽  
Aquatic Life ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Wide Range

Background: The cost of effluent treatment is not affordable by small scale industries especially in developing countries. Hence the effluent is discharged without treatment into water bodies. The dyes do not degrade easily and possess a major concern to be addressed. The aquatic life is highly affected and also leads to bio magnification of the chemicals through the food chain. Objective: To synthesize a ternary hybrid structure for enhanced photocatalytic activity under visible light. It is intended to reduce toxicity caused by dyeing units. Methods: Synthesized nanomaterials are characterized and used as photocatlyst for the degradation of methylene blue. In degradation experiment known weight of catalyst was added to known volume of an aqueous solution of dye at various concentrations. The solutions are aerated in dark for about 30 min. At the time of irradiation of light, known aliquot of the aqueous mixture was collected at an interval of constant time each from the reaction solution. The catalyst in the mixture was separated by centrifuging the mixture and absorbance was measured. The % of degradation of the dye can be determined knowing initial and final dye concentration. Result: Heterostructures are characterized with analytical tools such as X-ray diffraction, Fourier transform infrared spectroscopy. Band gap of photocatlyst is calculated by application of UV-Vis spectroscopy. Morphology is seen using scanning electron microscopy and transmission electron microscopy. Distribution of constituent structures is observed with energy-dispersive X-ray (EDX) spectroscopy. The structures are used for photocatalytic degradation of methylene blue dye solution under UV and visible light irradiation. Heterostructures showed best performance under visible light. Conclusion: The ternary hybrid nanostructure ZnO-MnO2-Gd2O3 was effectively prepared by a simple solution combustion method. The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. Structures showed better catalytic property under visible light.

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