scholarly journals Poly(catechol) modified Fe3O4 magnetic nanocomposites with continuous high Fenton activity for organic degradation at neutral pH

2021 ◽  
Author(s):  
Yani Hua ◽  
Chuan Wang ◽  
Sha Wang ◽  
Juan Xiao
Keyword(s):  
Catalytic Activity ◽  
Fenton Reaction ◽  
Organic Molecules ◽  
Precipitation Method ◽  
Organic Degradation ◽  
Redox Pair ◽  
Iron Leaching ◽  
Acidic Conditions ◽  
Ph Range ◽  
Co Precipitation

Abstract Fe3O4 magnetic nanoparticles (MNPs) have been widely used as a recyclable catalyst in Fenton reaction for organic degradation. However, the pristine MNPs suffer from the drawbacks of iron leaching in acidic conditions as well as the decreasing catalytic activity of organic degradation at a pH higher than 3.0. To solve the problems, Fe3O4 MNPs were modified by poly(catechol) (Fe3O4/PCC MNPs) using a facile chemical co-precipitation method. The poly(catechol) modification improved both the dispersity and the surface negative charges of Fe3O4/PCC MNPs, which are beneficial to the catalytic activity of MNPs for organics degradation. Moreover, the poly(catechol) modification enhanced the efficiency of Fe(II) regeneration during Fenton reaction due to the acceleration of Fe(III) reduction by the phenolic/quinonoid redox pair. As a result, the Fenton reaction with Fe3O4/PCC MNPs could efficiently degrade organic molecules, exampled by methylene blue (MB), in an expanded pH range between 3.0 and 10.0. In addition, Fe3O4/PCC MNPs could be reused up to 8 cycles for the MB degradation with negligible iron leaching of lower than 1.5 mg L-1. This study demonstrated Fe3O4/PCC MNPs are a promising heterogeneous Fenton catalysts for organic degradation.

Preparation and Analysis of Magnetic Nanoparticles Used as Highly Active Catalysts over a Wide pH Range

2012 ◽  
Vol 424-425 ◽  
pp. 1057-1061
Author(s):  
Wei Wang ◽  
Tie Long Li ◽  
Ying Liu
Keyword(s):  
Magnetic Nanoparticles ◽  
Precipitation Method ◽  
Fe3o4 Magnetic Nanoparticles ◽  
Ph Adjustment ◽  
Highly Active ◽  
Wide Range ◽  
Iron Leaching ◽  
Wide Ph Range ◽  
Ph Range ◽  
Co Precipitation

In this work, Fe3O4 magnetic nanoparticles with high peroxidase-like catalytic activity and spontaneous pH adjustment ability were successfully prepared by co-precipitation method followed by appropriate thermal treatment. Key synthesis factors were identified and adjusted to tailor the crystallinity, chemical composition and then catalytic property. The crystal structure and Fe (II) content of the catalyst strongly affected its degradation efficiency. Phenol was completely removed by the optimal magnetic nanoparticles under a wide range of pH from 3.0 to 8.0. Additionally, this catalyst exhibited low iron leaching, good reusability and excellent potential to eliminate various organic pollutants from waste water. The reaction mechanism was discussed in terms of the formation of HO• and O2•−/HO2• radicals.

High Catalytic Activity and Stability of Hexaaluminate Catalysts for N2O Decomposition

2013 ◽  
Vol 320 ◽  
pp. 665-669
Author(s):  
Chao Zhang ◽  
Yong Ji Song ◽  
Feng Hua Shi ◽  
Cui Qing Li ◽  
Hong Wang
Keyword(s):  
Catalytic Activity ◽  
Decomposition Reaction ◽  
Precipitation Method ◽  
High Catalytic Activity ◽  
Structure And Properties ◽  
Active Components ◽  
Co Precipitation ◽  
Hexaaluminate Catalysts

In this paper, hexaaluminate oxides LaMAl12O19-σwere prepared by using M=Cu ,Ce and Zn as active components to substitute Al in the hexaaluminate lattice by co-precipitation method. The structure and properties of LaMAl11O19-σcatalyst was characterized with XRD and BET. The results showed LaCuAl11O19-σexhibited significant high catalytic activity for the decomposition reaction of N2O. Under the simulated in situ condition, LaCuAl11O19-σalso indicated significant catalytic activity and stability, with N2O conversion of 90% at 635°C.

Study on the Preparation of Nano Fe3O4 Powder and its Properties

2012 ◽  
Vol 178-181 ◽  
pp. 562-565
Author(s):  
Rui Cui Liu ◽  
Fu Yi Jiang ◽  
Zi Quan Liu
Keyword(s):  
Catalytic Activity ◽  
Rhodamine B ◽  
Catalytic Degradation ◽  
Model Reaction ◽  
Iron Chloride ◽  
Precipitation Method ◽  
Photo Catalytic Activity ◽  
Powder Samples ◽  
Nano Fe3o4 ◽  
Co Precipitation

The experiment used iron chloride, iron dichloride and other agents as the main resources to prepare the nano Fe3O4 powder by co-precipitation method. Magnets were used to test the magnetism of the prepared nano Fe3O4 powder samples. And the photo-catalytic degradation of rhodamine B solution was used as the model reaction to test the photo-catalytic activity of the prepared nano Fe3O4 powder. The results showed that the prepared nano Fe3O4 powder samples had good magnetism but low photo-catalytic activity.

scholarly journals Arsenic removal from water by Zr-γ- FeOOH nanoparticles

2019 ◽  
Vol 2 (1) ◽  
pp. 112-120
Author(s):  
Nguyen Dinh Trung ◽  
Le Thi Ha Lan
Keyword(s):  
Ammonium Chloride ◽  
Arsenic Removal ◽  
Precipitation Method ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Adsorption Data ◽  
Wide Ph Range ◽  
Ph Range ◽  
Co Precipitation ◽  
Competitive Ions

Zr-γ-FeOOH nanoparticle adsorbent for As(V) and As(III) removal was prepared by a chemical co-precipitation method. Compared with γ-FeOOH, the addition of Zr enhanced the adsorptive capacities of As(V) and As(III). The maximum adsorptive capacities for As(V) and As(III) were 69.81 and 94.25 mg/g, respectively (rate Fe:Zr =1:0.5) at pH= 7.0. The adsorption data accorded with Langmuir and Freundlich isotherms. The adsorption of As(III) by Zr- γ-FeOOH was found to be effective in wide pH range of 6–8. Competitive ions hindered the adsorption according to the decreasing sequence phosphate, sulfate, ammonium, chloride, magnesium and calcium. The high adsorptive capability and good performance on other aspects make the Zr-γ- FeOOH nanorods a promissing adsorbent for the removal of As(V) and As(III) from groundwater.

scholarly journals Preparation of Metal Oxides Containing ppm Levels of Pd as Catalysts for the Reduction of Nitroarene and Evaluation of Their Catalytic Activity by the Fluorescence-Based High-Throughput Screening Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Co Precipitation

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.

Methane decomposition over unsupported mesoporous nickel ferrites: effect of reaction temperature on the catalytic activity and properties of the produced nanocarbon

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 68081-68091 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob ◽  
Mohd Sobri Takriff
Keyword(s):  
Catalytic Activity ◽  
Reaction Temperature ◽  
Methane Decomposition ◽  
Precipitation Method ◽  
Decomposition Of Methane ◽  
Thermocatalytic Decomposition ◽  
Co Precipitation

Unsupported mesoporous nickel ferrites were successfully synthesized via a facile co-precipitation method and used for the thermocatalytic decomposition of methane into hydrogen and nanocarbon at various reaction temperatures.

Immobilization of Salicylic Acid on Ni-Zn Layered Hydroxide Salts

2020 ◽  
Vol 840 ◽  
pp. 566-572
Author(s):  
Muhammad Robith Tahta Amnillah ◽  
Suyanta Suyanta ◽  
Sri Juari Santosa
Keyword(s):  
Salicylic Acid ◽  
Freundlich Isotherm ◽  
Point Of Zero Charge ◽  
Precipitation Method ◽  
Isotherm Models ◽  
Basal Spacing ◽  
X Ray ◽  
Dependent Property ◽  
Ph Range ◽  
Co Precipitation

Ni-Zn Layered hydroxide salt (Ni-Zn LHS) has been synthesized from equimolar Ni(NO3)2 and Zn(NO3)2 by co-precipitation method using NaOH. The formation of layered assembly is confirmed in X-ray diffractogram, i.e. by the appearance of peaks at 2θ: 9.60°, 19.40°, 33.48°, and 59.76° which corresponds to diffraction plane (001), (003), (020), and (040), respectively. The synthesized Ni-Zn LHSs possessed the point of zero charge (pHpzc) at pH 8 and nitrate as the interlamellar ion. The incorporation of salicylic acid into LHS can extend the property of LHS as a reductive adsorbent in the application of metal recovery. The immobilization of salicylic acid on the Ni-Zn-LHS was successfully done and indicated the strong pH-dependent property. The immobilization of salicylic acid on Ni-Zn LHSs was optimum at pH 7 and followed better the Langmuir than Freundlich isotherm models with immobilization capacity 64.93 mg/g. After the immobilization of salicylic acid, the basal spacing of Ni-Zn LHSs did not enlarge indicating that the immobilized salicylic acid was on the outer layer without entering the interlayer and this immobilized salicylic acid was stable at medium pH range 3 to 9.

scholarly journals Synthesis, Characterization and Catalytic Activity of NiO-CoO-MgO Nano-Composite Catalyst

2019 ◽  
Vol 19 (3) ◽  
pp. 675
Author(s):  
Salih Hadi Kadhim ◽  
Tariq Hussein Mgheer ◽  
Hussein Idrees Ismael ◽  
Khudheyer Jawad Kadem ◽  
Ahmed Saadon Abbas ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxides ◽  
Irradiation Time ◽  
Precipitation Method ◽  
Composite Catalyst ◽  
Celestine Blue ◽  
Force Microscopy ◽  
Atomic Force ◽  
Co Precipitation ◽  
Microscopy Techniques

The ternary NiO-CoO-MgO catalyst in three ratios 20:20:60, 25:25:50, and 30:30:40 for these component oxides respectively, were synthesized by co-precipitation method of their carbonates by addition of a precipitate agent in basic media, and then calcinated these carbonate to obtain of mixed oxides. The prepared catalysts were characterized by using Powder X-Ray Diffraction (PXRD), Fourier Infrared spectroscopy (FT-IR), and Atomic Force Microscopy techniques (AFM) were used for identification of the prepared catalysts. The result showed that the particle size of these catalyst ratios, were in the nano range and the smallest size was 25:25:50. The investigation of catalytic activity of prepared catalysts was done by photo decolorization of Celestine blue B dye from simulated industrial wastewaters in aqueous solution. The decolorization efficiency of dye reached 99.9% after irradiation time for 1 h. Study the effect of different reaction conditions such as the pH of the medium, the weight of semiconductor and temperature of mixture reaction were shown that the maximum degradation was observed in conditions at pH = 4, catalyst dosage = 0.08 g, and temperature = 303 K.

Effect of Cerium on Manganese Base Catalysts by Co-Precipitation for Low-Temperature SCR of NO with NH3

2014 ◽  
Vol 633 ◽  
pp. 121-124 ◽  
Author(s):  
Liang Jing Zhang ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Xiao Yu Ma ◽  
Xiao Gen Luo
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Precipitation Method ◽  
Base Catalysts ◽  
Nox Conversion ◽  
Scr Of No ◽  
Co Precipitation ◽  
Low Temperature Scr

Catalysts of Mn/TiO2 and Mn-Ce /TiO2 prepared by co-precipitation method for low temperature selective catalytic reduction (SCR) of NO with NH3 were investigated in this study. The experimental results showed that co-precipitation method after improvement, the NO conversion of Mn-Ce/TiO2 catalyst increased sharply. Meanwhile, the addition of cerium has significant effects on the catalytic activity. Characterizations of catalysts were carried out by XRD, BET and H2-TPR. The characterized results indicated that co-precipitation method after improvement, in temperature windows 150 to 300 °C, showed higher NOx conversion.

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