Effect of pH on the Properties of BiVO4 by Hydrothermal Synthesis Method

2018 ◽  
Vol 281 ◽  
pp. 813-818 ◽  
Author(s):  
Xin Liu ◽  
Jia Ke Li
Keyword(s):  
Methylene Blue ◽  
Raw Materials ◽  
Synthesis Method ◽  
Precursor Solution ◽  
X Ray Diffraction ◽  
Synthetic Sample ◽  
Photocatalytic Ability ◽  
Synthetic Product ◽  
Strong Adsorption ◽  
Blue Solution

Bismuth vanadate (BiVO4 ) powders were synthesized using Bi (NO3)3.5H2O and NH4VO3 as raw materials, NaOH and HNO3 for pH adjustment. The samples were characterized by X-ray diffraction ( XRD ), scanning electron microscopy (SEM ) and UV-vis diffuse reflectance spectra techniques. The results show that the pH of precursor solution has great effect on the composition and morphology of products. Synthetic product was BiVO4 with two kinds of crystal shape ( monoclinic and tetragonal ) with pH of 3; synthetic product was pure monoclinic phase BiVO4 when the pH is between 5-9. Whereas, V2O5 and Bi2O3 appeared when the pH was 11; synthetic product was a mixture of V2O5 and Bi2O3 with pH of 13, and BiVO4 don’t exist. The photocatalytic activity was evaluated by the degradation of methylene blue solution. It is shown that the synthetic sample has the best photocatalytic ability with pH of 5. The degradation of methylene blue reaches 84.7% when irradiated for 240 min by high pressure mercury lamp, and the sample synthesized at 13 for pH has strong adsorption capacity and poor photocatalytic ability.

Fast Synthesis of Ag3PO4 Cube Microcrystals and its High Visible-Light-Driven Photocatalytic Activities

2013 ◽  
Vol 401-403 ◽  
pp. 787-791
Author(s):  
Li Guo ◽  
Lin Lin Yue ◽  
Dan Jun Wang ◽  
Feng Fu
Keyword(s):  
Methylene Blue ◽  
Raw Materials ◽  
Metal Halide ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Metal Halide Lamp ◽  
Photocatalytic Activities ◽  
Visible Light Driven ◽  
Blue Solution ◽  
Fast Synthesis

Ag3PO4 photocatalyst was successfully synthesized via a aqueous precipitation process using AgNO3, NH3·H2O and NH4H2PO4 as raw materials, and characterized by X-ray diffraction (XRD),solid-UV-Vis and FE-SEM techniques. Photodegradation of Methylene blue solution,Rhodamine B,was studied with Ag3PO4 under experiment light recourse of metal halide lamp . The XRD result showed that the sample Ag3PO4 synthesized in a high purity belongs to tetragonal. And the sample has a strong absorption between 200 nm and 400 nm analysized by UV-Vis. The photodegradation experiment showed that Methylene blue solutionRhodamine B was more easily photodegradated with Ag3PO4 and light recourse was metal halide lamp.

scholarly journals One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Gallic Acid ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
One Step ◽  
Detailed Assessment ◽  
Higher Temperature

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

Synthesis of Visible-Light Responsive CdS/ZnO Nanocomposite Photocatalysts via Simple Precipitation Method

2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Methylene Blue Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blue Solution ◽  
Scanning Electron

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.

Temperature Dependence of LiMn2O4 Prepared by a Solution Combustion Synthesis in the System of Acetate Salts and Acetic Acid

2012 ◽  
Vol 485 ◽  
pp. 465-468
Author(s):  
Li Li Zhang ◽  
Gui Yang Liu ◽  
Jun Ming Guo ◽  
Bao Sen Wang ◽  
Ying He
Keyword(s):  
Acetic Acid ◽  
Combustion Synthesis ◽  
Raw Materials ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Electrochemical Performances ◽  
Metal Foil ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Acid Ratio

Spinel LiMn2O4 have been prepared by the solution combustion synthesis method using acetate salts as raw materials and acetic acid as fuel. The phase compositions of the as-prepared products were determined by X-ray diffraction (XRD). The electrochemical performance of the products was tested by using a coin-type half battery versus lithium metal foil as anode material. XRD results suggested that the purities of the products prepared at 500oC are higher than these of the products prepared at 600oC. For the products prepared at 500oC, the purities of the products increase with increasing acetic acid ratios. But for the products prepared at 600oC, the purities of the products decrease with increasing acetic acid ratios. The performance tests indicated that the electrochemical performances of the products prepared at 500oC are better than these of the products prepared at 600oC. The product prepared at 500oC with the acetic acid ratio of 1.0 gets the best performance. The initial capacity of it reaches to 124.8mAh/g at the current density of 75mA/g, and after 50 cycles, the capacity retention is 93.7%.

LiAl0.1Mn1.9O4 Prepared by a Solution Combustion Synthesis Using Acetate as Raw Materials and Acetic Acid as Fuel: Effect of Further Calcination Time

2012 ◽  
Vol 485 ◽  
pp. 473-477
Author(s):  
Gui Yang Liu ◽  
Jun Ming Guo ◽  
Li Li Zhang ◽  
Jing Wang ◽  
Bao Sen Wang ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Raw Materials ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Metal Foil ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
Solution Combustion ◽  
X Ray ◽  
Discharge Capacities

LiAl0.1Mn1.9O4 materials were prepared by a solution combustion synthesis method. In order to improve the purity of the products, the effect of further calcination time was investigated. The phase compositions of the as-prepared products were determined by X-ray diffraction (XRD). The electrochemical performance of the products was tested by using a coin-type half battery versus lithium metal foil as anode material. XRD results suggested that the main phase of the products was LiAl0.1Mn1.9O4, and there was a trace amount Mn2O3 impurity in some of the products. The purity, crystallinity and grain size of the LiAl0.1Mn1.9O4 were increased with increasing further calcination time. Electrochemical experiments demonstrate that the initial discharge capacities of the products with further calcination time of 0, 6, 12 and 24h were 93.7, 105.7, 114.0 and 120.6mAh/g, and about 89.8, 89.5, 89.2 and 88.3% of the initial capacities were retained after 25 cycles, respectively. Further calcination time can enhance the initial capacity, but is not favorable for the cycle ability of the products.

Ni Doped LiMn2O4 Prepared by a Flameless Combustion Synthesis

2012 ◽  
Vol 625 ◽  
pp. 251-254 ◽  
Author(s):  
Gui Yang Liu ◽  
Bao Sen Wang ◽  
Ying He ◽  
Jun Ming Guo
Keyword(s):  
Combustion Synthesis ◽  
Raw Materials ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Solution Combustion ◽  
Limn2o4 Spinel ◽  
X Ray

In this paper, LiNixMn2−xO4 materials were prepared by solution combustion synthesis method using acetic salts as raw materials and acetic acid as fuel. The phase structures are characterized by X-ray diffraction (XRD). Electrochemical performances of the materials are investigated by galvanostatic charge/discharge methods. XRD results revealed that the main phase of the products with increasing Ni3+ content is LiMn2O4, and there is a trace amount of Mn3O4 found in the product with Ni3+ content of 0.05. Electrochemical experiments showed that the capacity and the cyclability of the LiNixMn2−xO4 materials decrease with increasing Ni3+ content. Ni3+ doping has no significantly improvement for the capacity and the cyclability of the LiMn2O4 spinel.

Adsorption Behavior of Methylene Blue with Quaternary Ammonium Modified Chitosan Microspheres Resin

2014 ◽  
Vol 924 ◽  
pp. 281-301
Author(s):  
Xing Mei Guo ◽  
Yu Fei Chen ◽  
Qiu Yun Zhang ◽  
Li Xuan Zeng ◽  
Ji Wen Luo
Keyword(s):  
Methylene Blue ◽  
Quaternary Ammonium ◽  
Freundlich Isotherm ◽  
Adsorption Behavior ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
Adsorption Effect ◽  
Modified Chitosan ◽  
Strong Adsorption ◽  
Ft Ir

Chitosan (CTS) is the partly deacetylated product of Chitin. It contains hydrogen bond and ionic bond, which can form a cage-like molecular network structure and thus it has a strong adsorption. According to the presence of hydroxyl and amino groups of the chitosan, through chemical modification, introduces different groups in repeating units become possible. In this article, different component of the rectorite (REC) were used to intercalate the chitosan in order to have the quaternary ammonium modification. Through this process we could obtain three kinds of chitosan/rectorite modified products. Besides, their structures were observed by using the X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). This paper also explained the examination of the adsorption effect of three kinds of chitosan/ rectorite modified products to the methylene blue under different conditions. Whats more, it also discussed the main factors of this effect. The results showed that the three adsorption behavior of adsorbents can be described by using the Freundlich isotherm model. In three kinds of chitosan/ rectorite modified products, 4:1 CTS/REC-ETA demonstrated the best adsorption. Followed was the 2:1 CTS/REC-ETA. And the 8:1 CTS/REC-ETA was the weakest.

scholarly journals Preparation of Multicycle GO/TiO2 Composite Photocatalyst and Study on Degradation of Methylene Blue Synthetic Wastewater

2019 ◽  
Vol 9 (16) ◽  
pp. 3282 ◽  
Author(s):  
Zhongtian Fu ◽  
Song Zhang ◽  
Zhongxue Fu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Raw Materials ◽  
Anatase Phase ◽  
Pure Tio2 ◽  
Synthetic Wastewater ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Composite Photocatalyst ◽  
Initial Ph

A series of composite photocatalysts were prepared by using graphene oxide (GO) prepared by modified Hummers method and TiO2 hydrogel prepared by using butyl titanate as raw materials. The composite photocatalyst was characterized through scanning electron microscope（SEM）, x ray diffraction （XRD）, and Raman spectroscopy, and the degradation effect of pure TiO2 and composite photocatalyst on methylene blue (MB) dye wastewater under different experimental conditions was studied. The results showed that TiO2 in composite photocatalyst was mainly anatase phase and its photocatalytic activity was better than pure TiO2. When the addition of GO reached 15 wt%, the photocatalytic activity was the highest. When 200 mg composite photocatalyst was added to 200 mL synthetic wastewater with a concentration of 10 mg/L and an initial pH of about 8, the degradation rate could reach 95.8% after 2.5 h. It is presumed that the photogenerated charges of GO/TiO2 composite photocatalyst may directly destroy the luminescent groups in the MB molecule and thus decolorize the wastewater, and no other new luminescent groups are generated during the treatment.

Fabrication and characterization of Fe2O3, Bi2O3 and BiFeO3 and evaluation of their photo catalytic performances on degradation of methylene blue dye

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fiza Akram ◽  
Muhammad Saeed ◽  
Javaid Akhtar ◽  
Syed Ali Raza Naqvi ◽  
Atta ul Haq
Keyword(s):  
Methylene Blue ◽  
Free Energy ◽  
Dye Degradation ◽  
Precipitation Method ◽  
Blue Dye ◽  
X Rays ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Blue Solution

Abstract This study reports the fabrication of Fe2O3, Bi2O3, and BiFeO3, characterization and evaluation of the photocatalytic performances for methylene blue dye degradation. The materials were synthesized by precipitation method and characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-rays analyses, and Fourier transform infrared analyses. The photocatalytic activities of Fe2O3, Bi2O3, and BiFeO3 were compared by performing degradation experiments with 50 mL of 100 mg/L methylene blue solution. The as-prepared BiFeO3 was found as 2.4 times and 1.7 times more effective than Fe2O3 and Bi2O3, with a 79, 47, and 57% catalytic activity, respectively. The degradation of methylene blue over the BiFeO3 catalyst was optimized in terms of pH, catalyst dosage, temperature, and methylene blue concentration. The Eley–Rideal mechanism was proposed to describe the reaction kinetics in terms of the first order and second order kinetics model. Activation energy E (kJ/mol), enthalpy ΔH (kJ/mol), entropy ΔS (J/mol) and free energy ΔG (kJ/mol) were calculated as 20.8, 18.2, 197.5 and −45.3 respectively. The negative value of free energy shows that photodegradation is favored in present conditions.

Effect of Polyvinyl Pyrrolidone Dosage on Barium Ferrite Fibers via Electrospinning

2016 ◽  
Vol 848 ◽  
pp. 333-338
Author(s):  
Yue Guang Chen ◽  
Gui Fang Liu ◽  
Shi Jiao Wang
Keyword(s):  
Barium Ferrite ◽  
Raw Materials ◽  
Precursor Solution ◽  
Vinyl Pyrrolidone ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Vibration Sample Magnetometer ◽  
Poly Vinyl Pyrrolidone ◽  
Xrd Patterns

Barium ferrite micro/nanofibers were successfully prepared via the electrospinning by using dimethyl formamide (DMF) as the solvent, poly vinyl pyrrolidone (PVP) as the spinning auxiliaries and iron nitrate and barium nitrate as raw materials. The effect of poly vinyl pyrrolidone on the structure, morphology, magnetic and microwave absorbing properties were investigated by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), vibration sample magnetometer (VSM) and vector network analyzer (VNA). XRD patterns of the samples confirmed that when the additive content of PVP was up to 10%, (wt%) pure barium ferrite fibers formed under the condition of the same heat treatment. Also, the FE-SEM images showed that the morphology of the fibers improved with the increase of PVP content. Moreover, the VSM results demonstrated that the saturation magnetization can reach 54.7 emu/g when the PVP dosage is 14% (wt%) in the precursor solution.

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