scholarly journals Electrochemically Crafted Monodispersed γ-Cu5Zn8 Bimetallic Nanoalloy: Characterization and Its Synergistic Effect on Photocatalysis and Antibacterial Efficacy

Author(s):  
R. Singaravelan ◽  
M. Shanmugam ◽  
A. Abdul Salam ◽  
P. Vasanthi ◽  
M. Magesh ◽  
...  

Abstract The present work reports the investigation of monodispersed nano brass prepared by the facile electrochemical technique. The influence of reaction conditions on the surface morphology and size of the bimetallic nano alloy were investigated through high resolution scanning electron microscopy (HR-SEM) and powder X-ray diffraction (PXRD) technique. From the powder XRD analysis the nano alloy was identified as a [[EQUATION]] phase. The detailed investigation was carried out using transition electron microscope (TEM) for the textural features and γ-CuZn phase stoichiometry was revealed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDAX) analyses. Optical responses were analysed using diffuse reflectance spectroscopy (DRS). The energy band gap obtained from the optical spectrum revealed it can be a good catalyst. Rate of photocatalytic reaction and mechanism of degradation were discussed in detail. Most importantly, electrodeposited γ-CuZn nano alloy reveals superior nano-catalytic activity on methyl orange dye degradation in the shorter irradiation time. Furthermore, the antimicrobial efficacy of the γ-CuZn nano alloy was examined using gram positive and gram negative bacterial strains.

2019 ◽  
Vol 35 (3) ◽  
pp. 1037-1044
Author(s):  
Sagar Kande ◽  
Udhav Ghoshir ◽  
Jayshree Khedkar ◽  
Anil Gambhire

A series of novel photocatalyst with CdS loaded on activated carbon (xAC/CdS) were successfully synthesized by a simple hydrothermal method. The activated carbon content was varied between 0-7 wt. %. The prepared photocatalysts were characterized by X-ray diffraction, scanning electron microscopy with EDX, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, N2 adsorption-desorption analysis and photoluminescence spectroscopy. The photocatalytic activity of as-synthesized photocatalysts was studied for RhB dye degradation under natural sunlight irradiation. XRD analysis assigned both cubic and hexagonal morphology for xAC/CdS photocatalysts. The UV-vis DRS studies showed that loading of CdS on activated carbon enhances its visible light absorption with decrease in band gap energy. The lowest photoinduced e/h pair recombination rate in 3wt% AC/CdS results in optimum photocatalytic activity as revealed by photoluminescence study. The enhancement in dye degradation ability (̴ 11 times) of prepared photocatalysts can be attributed to synergistic effect of CdS and activated carbon.


2007 ◽  
Vol 124-126 ◽  
pp. 1229-1232 ◽  
Author(s):  
Myoung Seok Sung ◽  
Yoon Bok Lee ◽  
Yong Jin Kim ◽  
Yang Do Kim

Cadmium selenide(CdSe) nanoparticles were prepared in the aqueous solution containing isopropyl alcohol by the ultrasonic irradiation at room temperature. The cadmium chloride (CdCl2) and sodium selenosulfate (Na2SeSO3) were used as the cadmium and selenium source, respectively. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-Vis absorption spectra and PL spectra were used to characterize the CdSe nanoparticles. XRD analysis revealed the formation of cubic structure CdSe. TEM images showed aggregated CdSe nanoparticles with the size of nanometer scale. Average size of CdSe nanoparticles were about 3.9, 5.0 and 5.1nm with sonication time of 6, 30 and 40 minutes, respectively. The surface emission became less intensive and shifted to red with increasing irradiation time. This paper presents the effects of ultrasonic on the formation of CdSe nanoparticles and its characteristics.


2021 ◽  
Vol 14 ◽  
Author(s):  
C.H. Yu ◽  
Z.Y. Xue ◽  
Y.J. Mao ◽  
J. F. Huang ◽  
F.H. Tao ◽  
...  

Background: Gentian violet dye released from industries into the environment has caused serious water pollution and is a significant environment pollutant to human beings owing to the toxicity. It is urgent to decrease the environmental pollution by removing gentian violet in the wastewater. Objective: The aim is to synthesize hexahydroxy strontium stannate/tin dioxide nanocomposites by a simple hydrothermal method without surfactants and research the photocatalytic performance for gentian violet degradation. Methods: Hexahydroxy strontium stannate/tin dioxide nanocomposites have been obtained via the hydrothermal method. The structure, size, morphology and photocatalytic performance were characterized by X-ray diffraction, electron microscopy, solid ultraviolet-visible diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Results : The nanocomposites possess oven-shaped morphology with the size of less than 100 nm and are composed of hexagonal SrSn(OH)6 and tetragonal SnO2 phases. The band gap of the nanocomposites is 3.52 eV. 10 mg hexahydroxy strontium stannate/tin dioxide nanocomposites have the ability to completely degrade 10 mL gentian violet solution with the concentration of 10 mgL-1 under 6 h ultraviolet-visible light irradiation. Hydroxyl radical, hole and superoxide radical are main species for the gentian violet photocatalytic degradation using the nanocomposites. Conclusion: The hexahydroxy strontium stannate/tin dioxide nanocomposites show good photocatalytic performance for the GV degradation. The photocatalytic performance for gentian violet degradation using the hexahydroxy strontium stannate/tin dioxide nanocomposites depends on the irradiation time and content of the nanocomposites.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Silija Padikkaparambil ◽  
Binitha Narayanan ◽  
Zahira Yaakob ◽  
Suraja Viswanathan ◽  
Siti Masrinda Tasirin

Nanogold doped TiO2catalysts are synthesized, and their application in the photodegradation of dye pollutants is studied. The materials are characterized using different analytical techniques such as X-ray diffraction, transmission electron microscopy, UV-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the strong interaction between the metallic gold nanoparticles and the anatase TiO2support. Au doped systems showed very good photoactivity in the degradation of dye pollutants under UV irradiation as well as in sunlight. A simple mechanism is proposed for explaining the excellent photoactivity of the systems. The reusability studies of the photocatalysts exhibited more than 98% degradation of the dye even after 10 repeated cycles.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
P. Nyamukamba ◽  
L. Tichagwa ◽  
S. Mamphweli ◽  
L. Petrik

Herein, we report the synthesis of quartz supported TiO2 photocatalysts codoped with carbon and silver through the hydrolysis of titanium tetrachloride followed by calcination at 500°C. The prepared samples were characterized by UV-Vis diffuse reflectance spectroscopy, high resolution scanning electron microscopy (HRSEM), Raman spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Codoping of TiO2 with Ag and carbon resulted in an increase in the surface area of the photocatalyst and altered the ratio of the anatase to rutile phase. The absorption edge of all the doped TiO2 photocatalysts redshifted and the band gap was reduced. The lowest band gap of 1.95 eV was achieved by doping with 0.5% Ag. Doping TiO2 using carbon as the only dopant resulted in a quartz supported photocatalyst that showed greater photocatalytic activity towards methyl orange than undoped TiO2 and also all codoped TiO2 photocatalysts under visible light irradiation.


Author(s):  
Akshatha Gangadhar ◽  
Abhilash Mavinakere Ramesh ◽  
Jagadish Krishnegowda ◽  
Srikantaswamy Shivanna

Abstract Photocatalytic degradation of the dyes was deliberated by altering the catalyst and dye concentrations. The Zirconium oxide/Multiwall carbon nanotube (ZrO2/MWCNT) catalyst was facilely synthesized by a hydrothermal synthesis method. The nanocomposite ZrO2/MWCNT was formed in hydrothermal condition 95 °C of low growth temperature. The physico-chemical properties were successfully characterized using X-ray diffraction, (XRD) Scanning Electron Microscope (SEM), Energy dispersive Spectroscopy (EDS), Dynamic light scattering (DLS) analysis, X-ray photoelectron spectroscopy (XPS). The presence of Orbicular shaped ZrO2 nanocrystallines and Multiwall carbon nanotube was characterized by XRD pattern shows the presence of ZrO2 and MWCNT with the 2θ peaks at 19.62, 22.5 & 30.2. The thermal behavior of the ZrO2/MWCNT partials was also investigated by differential thermal analysis, and their vibrational bands were identified by infrared spectroscopy. The photo catalytic degradation of methylene blue in industrial wastewater was observed under UV light irradiation using the synthesized ZrO2/MWCNT as catalyst. The results revealed that the ZrO2/MWCNT nanoparticles exhibited high degeneration with COD and TOC reducing from 241 mg/L and 148.00 mg/L to 2.34 mg/L and 1.26 mg/L respectively with the efficiency of 90–94% over 25–60 min duration of UV irradiation time. In comparison with the pristine Zirconium Oxide and MWCNT, the composite ZrO2/MWCNT nanoparticles exhibited more efficient, the durable and stable photo-catalytic activity during experiments.


2018 ◽  
Vol 78 (3) ◽  
pp. 487-495 ◽  
Author(s):  
Pelin Demircivi ◽  
Esra Bilgin Simsek

Abstract Zirconium/titanium/chitosan (Zr/Ti/CHT) composite catalysts were synthesized by sol-gel method using different chitosan amounts (5–20 wt.%) and their activity in the photocatalytic degradation of Orange II dye was evaluated for the first time. The results were compared with Zr/Ti, Zr/CHT and Ti/CHT catalysts. The composite catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy analysis. XRD analysis revealed that the Zr/Ti/CHT composite catalyst showed high crystallinity of anatase TiO2 phase. Photocatalytic experiments showed that adding CHT into the catalyst structure increased the photocatalytic degradation under visible light irradiation. Also, the first-order reaction rate constant, kapp, was calculated using the Langmuir–Hinshelwood (L-H) equation. The kapp values were found to be 0.009, 0.0013, 0.012 and 0.014 min−1 for Zr/Ti, Zr/CHT, Ti/CHT and Zr/Ti/CHT, respectively. According to stability tests, after the first cycle Orange II dye degradation was found to be 95%, while it was 37% after the fifth cycle. The results showed that the composite catalyst could be used several times for Orange II dye degradation.


Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1969
Author(s):  
Riccardo Scarfiello ◽  
Elisabetta Mazzotta ◽  
Davide Altamura ◽  
Concetta Nobile ◽  
Rosanna Mastria ◽  
...  

The surface and structural characterization techniques of three atom-thick bi-dimensional 2D-WS2 colloidal nanocrystals cross the limit of bulk investigation, offering the possibility of simultaneous phase identification, structural-to-morphological evaluation, and surface chemical description. In the present study, we report a rational understanding based on X-ray photoelectron spectroscopy (XPS) and structural inspection of two kinds of dimensionally controllable 2D-WS2 colloidal nanoflakes (NFLs) generated with a surfactant assisted non-hydrolytic route. The qualitative and quantitative determination of 1T’ and 2H phases based on W 4f XPS signal components, together with the presence of two kinds of sulfur ions, S22− and S2−, based on S 2p signal and related to the formation of WS2 and WOxSy in a mixed oxygen-sulfur environment, are carefully reported and discussed for both nanocrystals breeds. The XPS results are used as an input for detailed X-ray Diffraction (XRD) analysis allowing for a clear discrimination of NFLs crystal habit, and an estimation of the exact number of atomic monolayers composing the 2D-WS2 nanocrystalline samples.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
N. Cruz-González ◽  
O. Calzadilla ◽  
J. Roque ◽  
F. Chalé-Lara ◽  
J. K. Olarte ◽  
...  

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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