scholarly journals Effect of Precursors on the Growth and Physiochemical Properties of Bio-mimetic ZnFe2O4 Nanocomposites for Photoelectrochemical Application

2020 ◽  
Vol 49 (12) ◽  
pp. 3165-3174
Author(s):  
Mohd Faizal Md Nasir ◽  
Wan Ramli Wan Daud ◽  
Mohamad Azuwa Mohamed ◽  
Mohamad Hafiz Mamat ◽  
Saifollah Abdullah ◽  
...  

Zinc ferrite (ZnFe2O4) photocatalysts have been prepared with different types of zinc precursors using the bio-mimetic synthesis method. The kapok fibre (Ceiba pentandra (L.) Gaertn) used as a sacrificial template. The physiochemical of prepared bio-mimetic materials were carried out thoroughly in this work. The FESEM analysis in mimetic zinc ferrite catalysts shows a distinctly different structural transition under different precursors conditions. The acetate precursor formed a hollow tubular structure while other precursors formed a hierarchal fibril structure. X-ray diffraction analysis showed a distinctly different phase transition while UV-Vis spectroscopy recorded variable optical properties beneath different precursor conditions. The EDX and ATR-FTIR spectroscopy confirmed the formation of the pure composite after the annealing process. Different type of precursors that used have leads to tuneable of the magnetic properties of the prepared materials. Electrophoretic deposition (EPD) method has been used to fabricate the synthesized materials as photo-electrodes on the FTO substrate then evaluated for photoelectrochemical (PEC) application. Changing the precursors in the preparation method show a significant effect on physicochemical and PEC performance. The morphology and surface structure of the prepared catalysts are correlated with the alteration of the precursors, then attributed to the charge transfer properties of the photocurrent density in PEC system. The bio-templated zinc ferrite catalysts are promising photoanode in the photocatalytic activities. It is interesting to note that the various forms of multi-structure such as hollow fibril core-shell offers an enormous impact in designing active photocatalyst with superior performance.

2020 ◽  
Vol 49 (12) ◽  
pp. 3219-3228
Author(s):  
Mohd Faizal Md Nasir ◽  
Wan Ramli Wan Daud ◽  
Mohamad Azuwa Mohamed ◽  
Mohamad Hafiz Mamat ◽  
Saifollah Abdullah ◽  
...  

Zinc ferrite (ZnFe2O4) photocatalysts have been prepared with different types of zinc precursors using the bio-mimetic synthesis method. The kapok fibre (Ceiba pentandra (L.) Gaertn) used as a sacrificial template. The physiochemical of prepared bio-mimetic materials were carried out thoroughly in this work. The FESEM analysis in mimetic zinc ferrite catalysts shows a distinctly different structural transition under different precursors conditions. The acetate precursor formed a hollow tubular structure while other precursors formed a hierarchal fibril structure. X-ray diffraction analysis showed a distinctly different phase transition while UV-Vis spectroscopy recorded variable optical properties beneath different precursor conditions. The EDX and ATR-FTIR spectroscopy confirmed the formation of the pure composite after the annealing process. Different type of precursors that used have leads to tuneable of the magnetic properties of the prepared materials. Electrophoretic deposition (EPD) method has been used to fabricate the synthesized materials as photo-electrodes on the FTO substrate then evaluated for photoelectrochemical (PEC) application. Changing the precursors in the preparation method show a significant effect on physicochemical and PEC performance. The morphology and surface structure of the prepared catalysts are correlated with the alteration of the precursors, then attributed to the charge transfer properties of the photocurrent density in PEC system. The bio-templated zinc ferrite catalysts are promising photoanode in the photocatalytic activities. It is interesting to note that the various forms of multi-structure such as hollow fibril core-shell offers an enormous impact in designing active photocatalyst with superior performance.


Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4035
Author(s):  
Rizwan Ullah ◽  
Mehtab Khan ◽  
Rozina Khattak ◽  
Nadia Khan ◽  
Muhammad Sufaid Khan ◽  
...  

An in-situ chemical oxidative method was used to effectively synthesize a promising supercapacitor material based on PPy/ZrO2 composites. The synthesized materials were characterized by different analytical techniques, such as UV/visible (UV/Vis) spectroscopy, Fourier-transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The inclusion of ZrO2 into the PPy matrix was verified by vibrational spectra and structural analyses. The (TGA) results showed that incorporating ZrO2 into the polymeric matrix improved its thermal stability. In addition, the electrochemical properties of the synthesizedmaterials were investigated byusing cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD). The PPy/ZrO2 composite demonstrated excellent super capacitive performance, and high specific capacity of 337.83 F/g, with an exceedingly high energy density of 187.68 Wh/kg at a power density of 1000 W/kg. The composite materials maintain good stability after 1000 charge and discharge cycles, with 85% capacitance retention. The PPy/ZrO2 possesses a high capacitance, an attractive micro-morphology, and a simple synthesis method. The findings indicate that the PPy/ZrO2 composite could be a promising electrode material for high-performance supercapacitor applications.


2018 ◽  
Vol 7 (4) ◽  
pp. 372-379 ◽  
Author(s):  
Burcu Sümer Tüzün ◽  
Judit Hohmann ◽  
Bijen Kivcak

AbstractA green synthesis method of silver nanoparticles (AgNPs) usingCentaurea virgataLam. extract and the isolated compound eupatorin was investigated in this study. Ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis, X-ray diffraction analysis and zeta potential were used for characterization of AgNPs. The UV-Vis spectrum exhibited a characteristic absorption band at 420 nm for monodisperse nanoparticles. FTIR measurements also proved the formation. X-ray diffraction patterns showed peaks at (110) and (112), which are characteristic for hexagonal crystals and also showed peaks at (111), (200) and (240), which are characteristic for orthorhombic crystals. The TEM images of AgNPs show that the morphology of AgNPs was predominantly spherical. Obtained AgNPs were highly stable according to the zeta potential values. The nitric oxide scavenging activity, which is also related to anticancer activity, of AgNPs was evaluated. It can be concluded thatC. virgataLam. extract and eupatorin can be used as a reducing agent for potential antioxidant AgNP formation.


2009 ◽  
Vol 1171 ◽  
Author(s):  
Chao-Ming Huang ◽  
Guan T. Pan ◽  
Lung C. Chen ◽  
C.K. Thomas Yang ◽  
Wen S. Chang

AbstractVisible-light-driven Ag3VO4 photocatalysts were successfully synthesized using low-temperature hydrothermal synthesis method. Under various hydrothermal conditions, the structures of silver vanadates were tuned by manipulating the hydrothermal time and the ratio of silver to vanadium. X-ray diffraction (XRD) results reveal that the powders prepared in a stoichiometric ratio consisted of pure α-Ag3VO4 or mixed phases of Ag4V2O7 and α-Ag3VO4. With increasing the Ag-to-V mole ratio to 6:1, the resulting samples were identified as pure monoclinic structure α-Ag3VO4. UV-vis spectroscopy indicated that silver vanadate particles had strong visible light absorption with associated band gaps in the range of 2.2-2.5 eV. The sample synthesized in the excess silver exhibited higher photocatalytic activity than that synthesized in a stoichiometric ratio. The powder synthesized at silver-rich at 140℃ for 4 h (SHT4) exhibited the highest photocatalytic activity among all samples. The reactivity of SHT4 (surface area, 3.52 m2 g-1) on the decomposition of gaseous benzene was about 16 times higher than that of P25 (surface area, 49.04 m2 g-1) under visible light irradiation. A well developed crystallinity of Ag3VO4 of SHT 4 was considered to enhance the photocatalytic efficiency.


2020 ◽  
Vol 312 ◽  
pp. 172-178
Author(s):  
Valery A. Svetlichnyi ◽  
Elena D. Fakhrutdinova ◽  
Tatiana S. Nazarova ◽  
Sergei A. Kulinich ◽  
Olga V. Vodyankina

In the present work, bismuth-based nanoparticles of various compositions were obtained by pulsed laser ablation of a metallic bismuth target in water and air using a Q-switch Nd:YAG laser (wavelength of 1064 nm, pulse duration of 7 ns, frequency of 20 Hz, and pulse energy of 160 mJ). Then the samples were annealed in air at temperatures up to 600°C. A comparative analysis of the obtained powders was carried out using methods of X-ray diffraction, transmission electron microscopy, specific surface area measurements, IR-Fourier and UV-Vis Spectroscopy. The photocatalytic activity of the synthesized materials in the process of Rhodamine B decomposition under irradiation of a LED source (375 nm) was also studied.


2011 ◽  
Vol 04 (02) ◽  
pp. 175-178
Author(s):  
MAGDALENA OSIADŁY ◽  
PAWEŁ PASIERB ◽  
STANISŁAW KOMORNICKI ◽  
MIECZYSŁAW RȨKAS

Silver and yttrium dopants influence some physico-chemical properties of BaCeO 3 protonic conduction. Ag -acceptor dopant substituting Ba atom in BaCeO 3 compounds was studied for the first time. Ba 1-x Ag x Ce 1-y Y y O 3-δ (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.1) materials were synthesized by solid state reaction and by modified Pechini citric acid method. X-ray diffraction (XRD) and electrical properties measurements including open cell voltage (OCV) of electrochemical cells were used as experimental techniques. Basing on XRD results it was found that all synthesized materials crystallized in orthorhombic Pnma phase with some admixtures of other phases. Metallic Ag , CeO 2 or Y 2 O 3 with different concentrations were detected, depending on the composition, synthesis method and preparation details. DC electrical measurements showed that doping by Ag and Y decreased the total and ionic conductivities of the materials. The modification of charge transport properties was also observed, namely introduction of Ag led to the increase of electronic component of total electrical conductivity, especially at higher temperatures.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Feng-shan Zhou ◽  
Dai-mei Chen ◽  
Bao-lin Cui ◽  
Wei-heng Wang

Sodium montmorillonite (MMT) was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy; the results showed that TiO2and CdS nanoparticles were loaded on the surface of montmorillonite uniformly. N2adsorption-desorption experiment showed that the specific surface area of TiO2/montmorillonite nanocomposite made by this method can reach 200 m2/g and pore-size distribution was from 4 to 6 nm; UV-Vis showed that the recombination of CdS and TiO2enhanced visible-light absorption ability of samples of TiO2/montmorillonite and visible-light absorption ability increase with the increased of the adsorption of CdS.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1371
Author(s):  
Tihana Čižmar ◽  
Vedran Kojić ◽  
Marko Rukavina ◽  
Lidija Brkljačić ◽  
Krešimir Salamon ◽  
...  

In this study, titanium dioxide nanotubes were prepared by electrochemical anodization technique and modified with an aqueous solution of FeCl3 using hydrothermal synthesis method to control the amount and distribution of iron compounds on the anatase TiO2 nanotubes. The objective was to synthesize immobilized FeOOH@TiO2 or Fe2O3@TiO2 photocatalysts designed for the flow-through reactor systems; to investigate thermal treatment effect on the photocatalytic efficiency; to determine appropriate Fe-compounds concentration for the maximum photocatalytic activity improvement, and to explain the mechanism responsible for the enhancement. The photocatalysts were tested for the degradation of 1H-benzotriazole in water under UV/solar light irradiation. Up to two times increase in the photocatalytic activity was obtained when TiO2 nanotubes were modified with 0.8 mM Fe. At higher Fe concentrations (8 mM and 80 mM), the photocatalytic activity of the given photocatalysts decreased. To confirm the formation of FeOOH or Fe2O3 species, and to clarify the mechanism of photoactivity, X-ray diffraction (XRD), Raman spectroscopy (RS), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS) and UV-Vis spectroscopy were used.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 213
Author(s):  
Ammara Nazir ◽  
Shoomaila Latif ◽  
Syed Farooq Adil ◽  
Mufsir Kuniyil ◽  
Muhammad Imran ◽  
...  

The present work was carried out to synthesize bismuth ferrite (BFO) nanoparticles by combustion synthesis, and to evaluate the photocatalytic activity of synthesized bismuth ferrite nanoparticles against cefixime trihydrate. BFO nanoparticles were successfully synthesized using bismuth (III) nitrate and iron (III) nitrate by a combustion synthesis method employing different types of fuels such as maltose, succinic acid, cinnamic acid, and lactose. The effects of the different types of fuels on the morphology and size of the bismuth ferrite nanoparticles were investigated. Characterization of the as-obtained bismuth ferrite nanoparticles was carried out by different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy-Dispersive Spectroscopy (EDS), N2-sorption analysis, Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV–vis) spectroscopy. Photoluminescence studies were also carried out for the various bismuth ferrite nanoparticles obtained. Degradation of cefixime trihydrate was investigated under sunlight to evaluate the photocatalytic properties of the bismuth ferrite nanoparticles, and it was found that the bismuth ferrite nanoparticles followed first-order degradation kinetics in solar irradiation in the degradation of antibiotic, cefixime trihydrate.


2012 ◽  
Vol 531 ◽  
pp. 411-414
Author(s):  
Zhi Hong Fu ◽  
Xiang Zhu He ◽  
Xin Sun ◽  
Yong Xiu Wang

The olivine LiMnPO4 used as cathode materials was synthesized by the low combustion synthesis method, and modified by doping Y. Testing of X-ray diffraction (XRD),scanning electron microscopy (SEM),charge-discharge measurements was carried out for LiMnPO4/C cathode materials and the modified materials. The synthesized materials doping by Y exhibited standard olivine structure, nano-sized particles, discharge capacity of 122.9mAh.g-1 and good cycling performance. These results indicated that less Y doping could improve electrochemical kinetics of lithium ion extraction/insertion and significantly enhanced electrochemical activity.


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