scholarly journals Study on the efficient removal of azo dyes by heterogeneous photo-Fenton process with 3D flower-like layered double hydroxide

2020 ◽  
Author(s):  
Siqi Bao ◽  
Yuqi Shi ◽  
Youshan Zhang ◽  
Longjie He ◽  
Wangyang Yu ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Three Dimensional ◽  
Fenton Process ◽  
X Ray ◽  
Effective Removal ◽  
One Step ◽  
Fenton Oxidation Process ◽  
Double Hydroxide

Abstract As organic dyes are the main pollutants in water pollution, seeking effective removal solutions is urgent for humans and the environment. A novel environmentally friendly three-dimensional CoFe-LDHs (3D CoFe-LDHs) catalyst was synthesized by one-step hydrothermal method. Scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectra, X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller technique as well as UV-Vis diffuse reflectance spectra were used to characterize the prepared samples. The experimental results revealed that 3D CoFe-LDHs exhibited a rapid decolorization of methyl orange and Rhodamine B by heterogeneous photo-Fenton process after reaching the adsorption equilibrium, and the final decolorization efficiency reached 91.18% and 93.56%, respectively. On the contrary, the decolorizing effect of 3D CoFe-LDHs on neutral blue was relatively weak. The initial concentrations of azo dyes, pH and H2O2 concentration affected the decolorization of dyes and the catalyst maintained excellent reusability and stability after reuse over five cycles. The quenching experiments found that •OH, •O2− and h+ were the main active substances and reaction mechanisms were further proposed. The study suggests that the synergistic effect of photocatalysis and Fenton oxidation process significantly improved the removal of azo dyes and the synthesized catalyst had potentially promising applications for difficult-to-biodegrade organic pollutants in wastewater.

Synthesis, structure and photocatalytic degradation of organic dyes of a copper(II) metal–organic framework (Cu–MOF) with a 4-coordinated three-dimensional CdSO4 topology

2019 ◽  
Vol 75 (8) ◽  
pp. 1053-1059 ◽  
Author(s):  
Lin-Lu Qian ◽  
Zhi-Xiang Wang ◽  
Hai-Xin Tian ◽  
Min Li ◽  
Bao-Long Li ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Crystal Engineering ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
And Storage

Metal–organic frameworks (MOFs) have attracted much interest in the fields of gas separation and storage, catalysis synthesis, nonlinear optics, sensors, luminescence, magnetism, photocatalysis gradation and crystal engineering because of their diverse properties and intriguing topologies. A Cu–MOF, namely poly[[(μ2-succinato-κ2 O:O′){μ2-tris[4-(1,2,4-triazol-1-yl)phenyl]amine-κ2 N:N′}copper(II)] dihydrate], {[Cu(C4H4O4)(C24H18N10)]·2H2O} n or {[Cu(suc)(ttpa)]·2H2O} n , (I), was synthesized by the hydrothermal method using tris[4-(1,2,4-triazol-1-yl)phenyl]amine (ttpa) and succinate (suc2−), and characterized by IR, powder X-ray diffraction (PXRD), luminescence, optical band gap and valence band X-ray photoelectron spectroscopy (VB XPS). Cu–MOF (I) shows a twofold interpenetrating 4-coordinated three-dimensional CdSO4 topology with point symbol {65·8}. It presents good photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) under visible-light irradiation. A photocatalytic mechanism was proposed and confirmed.

scholarly journals The three-dimensional flower-like Bi 2 WO 6 assisted by ethanolamine through a microwave method for efficient photocatalytic activity

2019 ◽  
Vol 6 (3) ◽  
pp. 181422
Author(s):  
Xingchen Liu ◽  
SuZhen Wang ◽  
Song Wang ◽  
Han Shi ◽  
Xiaolong Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Catalytic Performance ◽  
Microwave Method ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray ◽  
One Step

The three-dimensional flower-like Bi 2 WO 6 was synthesized through a one-step microwave method (the reaction temperature was 434 K and the reaction took 10 min) with the assistance of ethanolamine (EA). The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, PL, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analysis. Methyl orange was used as target pollutant to evaluate the photocatalysis property of samples. Furthermore, the influence of the mechanism of EA on the structure and catalytic performance of Bi 2 WO 6 was discussed. The detailed characterizations revealed that the three-dimensional flower-like Bi 2 WO 6 was successfully synthesized with the assistance of EA. The results confirmed that EA significantly influenced the morphology of Bi 2 WO 6 products. The addition of EA can effectively alter the pressure of the reaction and improve the crystal phase and structure of Bi 2 WO 6 photocatalysts, enhancing the photocatalytic activity of samples and improving the photocatalytic efficiency. EA can serve as an assembling agent and structure-directing agent resulting in the formation of flower-like architectures. With the increase of the amount of EA, the as-prepared Bi 2 WO 6 sample gradually forms a flower-like structure, leading to a shorter time of light holes migrating to the surface of the catalyst. It makes the compound rate significantly decreased, and improves the photocatalytic efficiency of the sample.

Degradation of Odontologic X-Ray Film Developing Wastewaters by Photo-Fenton Process

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Luciana Igarashi-Mafra ◽  
Edmilson César Bortoletto ◽  
Maria Angelica Simões Dornella Barros ◽  
Amanda Cristina Alfredo Contrucci Sorbo ◽  
Naiara Aguiar Galliani ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Total Phenol ◽  
Process Conditions ◽  
Phenol Removal ◽  
Total Phenols ◽  
Fenton Process ◽  
X Ray ◽  
Control Factors ◽  
Fenton Oxidation Process ◽  
Wastewater Samples

Effluents from radiographic X-ray film developing processes feature a high contaminant load (COD about 70000 mg/L and total phenols concentration about 16956 mg/L). Photo-Fenton's are potentially useful oxidation processes for destroying toxic organic compounds in water. In these reactions, hydrogen peroxide is combined with ferrous or ferric iron in the presence of light to generate hydroxyl radicals (·OH). The photo-Fenton process was explored as a photochemical treatment to degrade wastewater from radiographic X-ray film developing processes coming from odontologic clinics. A response surface methodology was applied to optimize the photo-Fenton oxidation process conditions using total phenol removal as the target parameter to be optimized, and the reagent concentrations, as related to the initial concentration of organic matter in the effluent, and time and pH as the control factors to be optimized. The best results in terms of maximal total phenol removal and economic process were achieved when wastewater samples were treated at pH 5 in the presence of hydrogen peroxide and iron in the ratios [total phenols]:[H2O2] 1:3 w/w and [Fe2+]:[H2O2] 1:18 w/w and time 1 h.

scholarly journals Synthesis of Three-Dimensional Fe3O4/Graphene Aerogels for the Removal of Arsenic Ions from Water

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Aerogels ◽  
Transmission Electron ◽  
Potential Applications ◽  
Removal Of Arsenic

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.

Highly efficient carbonaceous nanofiber/layered double hydroxide nanocomposites for removal of U(VI) from aqueous solutions

2019 ◽  
Vol 107 (4) ◽  
pp. 299-309
Author(s):  
Shuqi Yu ◽  
Xiangxue Wang ◽  
Shunyan Ning ◽  
Zhongshan Chen ◽  
Xiangke Wang
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Layered Double Hydroxide ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Three Dimensional ◽  
Order Kinetic ◽  
Surface Bonding ◽  
Double Hydroxide ◽  
Shed Light

Abstract The three-dimensional (3D) carbonaceous nanofiber and Ni-Al layered double hydroxide (CNF/LDH) nanocomposite was successfully prepared by a facile one-step hydrothermal methodology. Characterization of scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), XRD, and Fourier transformed infrared spectroscopy (FTIR) provided a demonstration that the modified CNF/LDH nanocomposite possessed abundant functional groups, for instance, metal-oxygen surface bonding sites (Ni–O as well as Al–O) and free-metal surface bonding sites (C–O, C–O–C, as well as O–C=O). The elimination of representative radionuclide (i.e. U(VI)) on the CNF/LDH nanocomposite from aqueous solutions was explored as a key function of pH, ionic strength, contact time, reaction temperature as well as radionuclide preliminary concentrations with the use of the batch methodology. As revealed by the findings, the sorption of radionuclides on CNF/LDH nanocomposite adhered to the pseudo-second-order kinetic model as well as Langmuir model. The maximum elimination capacity of U(VI) amounted to be 0.7 mmol/g. The independent of ionic strength shed light on the fact that inner-sphere surface complexation mainly overpowered radionuclide uptake by the CNF/LDH nanocomposite, which was further verified through the combination of FTIR and XPS spectral analyses. The abovementioned analyses shed light on the fact that the CNF/LDH nanocomposite can be regarded as a latent material to preconcentration radionuclides for environmental remediation.

scholarly journals Microwave-assisted preparation of ZnS and ZnSe nanocrystals with different morphologies for photodegradation process of organic dyes

2019 ◽  
Author(s):  
Katarzyna Matras-Postolek ◽  
A. Zaba ◽  
S. Sovinska ◽  
D. Bogdal
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Zinc Sulphide ◽  
Conventional Heating ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Zinc sulphide (ZnS) and zinc selenide (ZnSe) and manganese-doped and un-doped with different morphologies from 1D do 3D microflowers were successfully fabricated in only a few minutes by solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained  nanocrystals, additionally the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The photocatalytic activity of ZnSe, ZnS, ZnS:Mn and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO) and Rhodamine 6G (R6G), respectively. The results show that Mn doped NCs samples had higher coefficient of degradation of organic dyes under ultraviolet irradiation (UV).

scholarly journals One-Step Acidic Hydrothermal Preparation of Dendritic Rutile TiO2 Nanorods for Photocatalytic Performance

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 683 ◽  
Author(s):  
Cheng Gong ◽  
Jun Du ◽  
Xiuyun Li ◽  
Zhenjie Yu ◽  
Jiansong Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Hydrothermal Method ◽  
Photocatalytic Performance ◽  
Three Dimensional ◽  
Tio2 Nanorods ◽  
Foil Surface ◽  
Rutile Tio2 ◽  
X Ray ◽  
One Step

Three-dimensional and dendritic rutile TiO2 nanorods were successfully fabricated on a Ti foil surface using a one-step acidic hydrothermal method. The TiO2 nanorods were characterized using X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and optical contact angle testing. The results showed that the nanorods with diameters of 100–500 nm and lengths of 100 nm to 1 μm were obtained on the Ti foil surface. The length and density of the TiO2 nanorods were perfect at the conditions of HCl concentration 0.5 mol/L, temperature 220 °C, and reaction time 12 h. The TiO2 nanorods formed parallel to the consumption of Ti and grew along the (110) direction having a tetragonal rutile crystal. The morphology of the nanorods possessed a three-dimensional structure. The contact angle of the nanorods was only 13 ± 3.1°. Meanwhile, the photocatalytic activities of the TiO2 nanorods were carried out using ultraviolet fluorescence spectrophotometry for the methyl orange detection, and the degradation was found to be about 71.00% ± 2.43%. Thus, TiO2 nanorods can be developed by a one-step acidic hydrothermal method using Ti foil simultaneously as the substrate with a TiO2 source; the TiO2 nanorods exhibited photocatalytic performance while being environment-friendly.

scholarly journals Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1298 ◽  
Author(s):  
Muhammad Arif Khan ◽  
Nafarizal Nayan ◽  
Shadiullah Shadiullah ◽  
Mohd Khairul Ahmad ◽  
Chin Fhong Soon
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Average Length ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Study ◽  
Transmission Electron ◽  
One Step ◽  
Controlled Morphology ◽  
Xrd Patterns

In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and −1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

Preparation of C, N and P co-doped TiO2 and its photocatalytic activity under visible light

2019 ◽  
Vol 12 (04) ◽  
pp. 1950045 ◽  
Author(s):  
Lin Zhao ◽  
Yanzhao Xie ◽  
Qiuyu Lin ◽  
Rongze Zheng ◽  
Yong Diao
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Soluble Starch ◽  
Doping Amount ◽  
X Ray ◽  
Composite Catalysts ◽  
One Step ◽  
Co Doped

A series of composite catalysts of C, N and P co-doped TiO2 were prepared by sol-gel method, using a biomass (soluble starch) dopant. The samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), fourier transform infrared (FTIR) spectroscopy. The results show that TiO2 is co-doped with C, N and P by one step. The resulting composite exhibited higher specific surface area, wider visible-light absorption band with respect to the pure TiO2. The sample calcined at 400∘C for 2[Formula: see text]h with a doping amount of 6[Formula: see text]g soluble starch showed the best electrochemical performance. The C, N and P co-doped TiO2 was also used for the degradation of methylene blue (MB) and degradation ratio was up to 98% in 80[Formula: see text]min under visible light irradiation.

Preparation, Characterization of Nonmetal Doped TiO2 Nanoparticles with their Excellent Photocatalystic Properties

2011 ◽  
Vol 183-185 ◽  
pp. 2254-2257
Author(s):  
Ying Wei Wang ◽  
Yu Fei Li ◽  
Pei Han Yang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Anatase Phase ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
Doped Titania ◽  
Nonmetal Doping

Nonmetal (S, P) doped titania nanoparticles were synthesized by a one step hydrothermal method. These samples were calcined with different temperature, the sample exist in anatase phase has much higher photocatalytic activity for methylene blue (MB) degradation. The visible response and the higher UV activity of the different nonmetal doped TiO2make it possible to utilize solar energy efficiently to execute photocatalysis processes. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc. It can conclude the nonmetal doping TiO2proves to be more suitable to improve the photocatalytic performance.

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