scholarly journals rGO Functionalized ZnO–TiO2 Core-Shell Flower-Like Architectures for Visible Light Photocatalysis

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 332
Author(s):  
Evangelia Vasilaki ◽  
Nikos Katsarakis ◽  
Spyros Dokianakis ◽  
Maria Vamvakaki
Keyword(s):  
Visible Light ◽  
Diffraction Field ◽  
Attenuated Total Reflectance ◽  
Blue Dye ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
X Ray ◽  
Visible Light Range ◽  
Reduced Graphene

Core-shell heterostructures with a complex, flower-like morphology, comprising a ZnO core and a TiO2 shell decorated with reduced graphene oxide (rGO) sheets by hydrothermal wrapping, are reported to extend the absorption properties of the semiconductors toward the visible light range. The ternary photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, diffuse reflectance UV–Vis, and attenuated total reflectance-Fourier transform infrared spectroscopy. Its photocatalytic performance was evaluated under visible light irradiation using methylene blue dye as a model pollutant. The rGO-modified ZnO–TiO2 photocatalyst exhibited superior photoactivity compared to that of the parent ZnO–TiO2 core-shell structures, which was dependent on its graphene content. The enhanced photocatalytic response was attributed to the higher absorption in the visible light range, as well as the pronounced electron and hole separation in the ternary system.

FeYO3@rGO nanocomposites: Synthesis, characterization and application in photooxidative degradation of atrazine under visible light

2021 ◽  
Vol 11 (5) ◽  
pp. 706-716
Author(s):  
Nada D. Al-Khthami ◽  
Tariq Altalhi ◽  
Mohammed Alsawat ◽  
Mohamed S. Amin ◽  
Yousef G. Alghamdi ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Structural Surface ◽  
Adsorption Desorption

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.

scholarly journals Effect of Oxalic Acid Leaching on Photocatalytic Activity of Natural Sphalerite

2020 ◽  
Author(s):  
Chukwunonso Onyenanu ◽  
Lovet Emembolu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Irradiation Time ◽  
Acid Leaching ◽  
Blue Dye ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Illumination

Abstract Photocatalytic activity of the natural semiconducting sphalerite mineral from Abuni, Nasarawa State, Nigeria was studied for the degradation of methylene blue (MB). Natural Sphalerite as a visible – light responsive photocatalyst was characterized by X ray diffraction (XRD), X ray fluorescence (XRF) and surface area analysis. To further enhance the photocatalytic activity of natural Sphalerite, the chemical composition of the sphalerite was varied via leaching with oxalic acids. The photocatalytic activity of the Natural sphalerite, leached sphalerite and as well as the calcined leachates was tested for MB degradation under visible light illumination. The result shows a very high percentage of MB degradation by natural sphalerite after 60mintues of light irradiation time. A composite of ZnO -α –Fe2O3 -ϒ-Fe2O3 with traces amount of MoO and MnO2 was synthesized by calcination of the obtained leachates at 1000°C for 4hours. The photocatalytic degradation of methylene blue dye follows pseudo first order kinetics.

scholarly journals Degradation of Methylene Blue Dye in the Presence of Visible Light Using SiO2@α-Fe2O3 Nanocomposites Deposited on SnS2 Flowers

2018 ◽  
Author(s):  
Sridharan Balu ◽  
Kasimayan Uma ◽  
Guan-Ting Pan ◽  
Thomas C.-K. Yang ◽  
Sayee Kannan Ramaraj
Keyword(s):  
Methylene Blue ◽  
Three Dimensional ◽  
Semiconductor Materials ◽  
Blue Dye ◽  
Core Shell ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

Semiconductor materials have been shown to have better photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 were synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL). The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was observed by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt. % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.

scholarly journals Fe + NNoncompensated Codoping TiO2Nanowires: The Enhanced Visible Light Photocatalytic Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongpo Zhou ◽  
Haiying Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Absorption Enhancement ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Activity Increase ◽  
X Ray ◽  
Visible Light Range

TheFe + Ncodoped nanowire samples are prepared by hydro-thermal method and annealed in NH3atmosphere. The XRD (X-ray diffraction), SEM (Scanning electron microscope), UV-vis absorption spectroscopy, and BET (Brunauer, Emmett, and Teller) results indicate that the samples are pure anatase nanowires. TheFe + Ncodoped samples have the highest specific surface area, the largest red-shift, and the largest absorption enhancement in the visible light range compared with Fe doped, N doped, and undoped nanowires. The measurements of XPS (X-ray photoelectron spectroscopy) show that N content ofFe + Ncodoped TiO2is about two times as large as that of the N doped TiO2. It is assumed that nitrogen doping plays a very important role for the photocatalytic activity increase and hence theFe + Ncodoped nanowire TiO2shows the most effective photocatalytic activity under the visible light irradiation.

Synthesis and Micro-Wave Absorption Properties of BiFeO3 Coated Fe Nanocapsules

2013 ◽  
Vol 712-715 ◽  
pp. 229-232 ◽  
Author(s):  
Gui Mei Shi ◽  
Da Wei Lu ◽  
Yan Zhang
Keyword(s):  
Reflection Loss ◽  
Photoelectron Spectrum ◽  
Core Shell ◽  
Absorber Thickness ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Thickness Layer

BiFeO3coated ferromagnetic Fe nanocapsules is synthesized by arc-discharging method. Typical HRTEM images show that the nanocapsules form in a core-shell structure. X-ray photoelectron spectrum (XPS) and X-ray diffraction (XRD) reveal that the core is ferromagnetic Fe, while the shell is BiFeO3/Bi2Fe4O9.The reflection loss R of less than -10 dB was obtained for the whole frequency within the 2-18GHz range by choosing an appropriate layer thickness between 1.0mm and 7.0mm. An optimal reflection loss of -21.5 dB was reached at 10.6 GHz with an absorber thickness of 2.0mm. It is worth noticing that the BiFeO3coated Fe nanocapsules have two absorption peaks below -10 dB at each thickness layer ranging from 4.0nm to 7.0nm, which means the composites nanocapsules absorber simultaneously are able to absorb microwaves in different band of several GHz.

Visible-Light Driven Effective Photocatalytic Degradation of Methylene Blue Dye Using Perforated Curly Zn0.1Ni0.9O Nanosheets

2020 ◽  
Vol 20 (9) ◽  
pp. 5759-5764
Author(s):  
V. Karthikeyan ◽  
G. Gnanamoorthy ◽  
P. Varun Prasath ◽  
V. Narayanan ◽  
Suresh Sagadevan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Organic Waste ◽  
Hydrothermal Process ◽  
Blue Dye ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Driven

Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.

Preparation and Photocatalytic Properties of Visible-Light-Driven BiVO4/attapulgite Composite

2013 ◽  
Vol 864-867 ◽  
pp. 601-604
Author(s):  
Jin Zhang ◽  
Yu Xin Sun
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Diffuse Reflectance ◽  
Energy Dispersive Spectrometry ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Range ◽  
Visible Light Driven ◽  
Uv Visible

A novel attapulgite clay-based composite (BiVO4/attapulgite) was successfully prepared as a heterogeneous photocatalyst for degradation of rhodamine B (RhB) dye solution under visible light irradiation. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and microanalysis by energy dispersive spectrometry (EDS), and UV-visible diffuse reflectance spectra (DRS). The results showed that monoclinic BiVO4particles were loaded successfully on to the surface of attapulgite fibers and were widely dispersed. The DRS spectrum reveals that the BiVO4/attapulgite composite had much stronger absorption in the visible light range of 420-800 nm. Correspondingly, the BiVO4/attapulgite composite showed significantly higher activity in degrading RhB solution under visible-light irradiation compared to that of pure BiVO4.

Cu(OH)2/N-TiO2 Compound Heterojunction Photcocatalyst: Preparation, Characterization and Photocatalytic Properties

2013 ◽  
Vol 652-654 ◽  
pp. 774-778
Author(s):  
Xiao Song Zhou ◽  
Bei Jin ◽  
Bin Yang
Keyword(s):  
Visible Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spherical Structure ◽  
Visible Light Range ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
20 Nm

Cu(OH)2/N-TiO2compound heterojunction photcocatalyst was prepared via a facile precipitation method. The as-synthesized samples were characterized by means of X-ray diffraction (XRD), field-emission transmission electron microscope (FE-SEM), ultraviolet-visible light (UV-vis) absorbance spectra technologies. The results suggest the as-obtained samples are spherical structure with the diameter of approximately 10-20 nm, the absorbance intensity in the visible light range increased with the amount of deposited increased. Photocatalytic activities of samples were investigated under visible light and methyl orange (MO) acted as simulation pollutants. The catalytic ablity of the synthesized photocatalysts under visible light irradiation showed higher than that of N-P25(TiO2). The remarkable photocatalytic activities are due to the high-quality of composites structure and the driving force for electron transfer in nanoparticle.

scholarly journals Visible light-assisted NGO-Fe3O4 composite activated peroxydisulfate for degradation of oxytetracycline

2020 ◽  
Vol 81 (4) ◽  
pp. 813-823
Author(s):  
Jing Bai ◽  
Junfeng Wu ◽  
Zhi Li ◽  
Zhaodong Wang ◽  
Zuwen Liu ◽  
...  
Keyword(s):  
Visible Light ◽  
High Performance ◽  
Degradation Efficiency ◽  
Precipitation Method ◽  
Liquid Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Doped ◽  
Reduced Graphene ◽  
Apparent Decrease

Abstract A nitrogen-doped reduced graphene oxide/Fe3O4 composite (NGO-Fe3O4) was prepared through the simplified hydrothermal and deposition-precipitation method and characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The degradation efficiency of oxytetracycline (OTC) by NGO-Fe3O4 activated peroxodisulfate (PDS) under visible light irradiation was studied. The degradation efficiency reached 100% within 32.5 min (the initial OTC concentration 50 mg L−1 and PDS 1 mM; [NGO-Fe3O4]:[ PDS] = 4:1; pH = 3.0). No apparent decrease in degradation efficiency was observed after five cycles. SO4−· and ·OH were the main active oxides for OTC degradation in this system. Moreover, four degradation pathways were proposed, namely hydroxylation, dehydration, decarbonylation and demethylation according to the analysis results of high-performance liquid chromatography mass spectrometry.

scholarly journals Preparation of CuCrO2 Hollow Nanotubes from an Electrospun Al2O3 Template

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1252 ◽  
Author(s):  
Hsin-Jung Wu ◽  
Yu-Jui Fan ◽  
Sheng-Siang Wang ◽  
Subramanian Sakthinathan ◽  
Te-Wei Chiu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Biomedical Application ◽  
Diffraction Field ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Interior Space ◽  
X Ray ◽  
Transmission Electron ◽  
Hollow Nanostructure ◽  
First Time

A hollow nanostructure is attractive and important in different fields of applications, for instance, solar cells, sensors, supercapacitors, electronics, and biomedical, due to their unique structure, large available interior space, low bulk density, and stable physicochemical properties. Hence, the need to prepare hollow nanotubes is more important. In this present study, we have prepared CuCrO2 hollow nanotubes by simple approach. The CuCrO2 hollow nanotubes were prepared by applying electrospun Al2O3 fibers as a template for the first time. Copper chromium ions were dip-coated on the surface of electrospun-derived Al2O3 fibers and annealed at 600 °C in vacuum to form Al2O3-CuCrO2 core-shell nanofibers. The CuCrO2 hollow nanotubes were obtained by removing Al2O3 cores by sulfuric acid wet etching while preserving the rest of original structures. The structures of the CuCrO2-coated Al2O3 core-shell nanofibers and CuCrO2 hollow nanotubes were identified side-by-side by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The CuCrO2 hollow nanotubes may find applications in electrochemistry, catalysis, and biomedical application. This hollow nanotube preparation method could be extended to the preparation of other hollow nanotubes, fibers, and spheres.

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