scholarly journals Facile synthesis of a high purity α-MnO2 nanorod for rapid degradation of Rhodamine B

2021 ◽  
Author(s):  
shumin wang ◽  
Ao Guan ◽  
Jiahan Wang ◽  
Xiaofang Fu ◽  
Xiang Guo ◽  
...  
Keyword(s):  
Rhodamine B ◽  
High Efficiency ◽  
Catalytic Mechanism ◽  
Ph Value ◽  
Removal Rate ◽  
Precipitation Method ◽  
Characteristic Peak ◽  
Catalytic Stability ◽  
Rapid Removal ◽  
Co Precipitation

Abstract Manganese dioxide (α-MnO2) nanorods with diameters of about 5-15 nm and lengths of 100-150 nm were synthesized by a simple co-precipitation method. XRD, TEM, HRTEM, SAED and XPS were used to analyze the crystallographic information, microstructure and chemical bonding of the as-prepared sample. The α-MnO2 nanorod exhibited a high efficiency and rapid removal rate of rhodamine B (RhB), which reached about 97.5% within 10 min when pH=4 (and pH=6.6) and 97.7% within 50 min when pH = 9 in the presence of H2O2. The results also indicated that a lower pH value is conducive to the movement of the characteristic peak and the attenuation of the intensity of the characteristic peak of RhB dye. Then a possible catalytic mechanism was revealed. Moreover, the α-MnO2 nanorod exhibits an excellent recyclability and catalytic stability. This research indicates that α-MnO2 nanorods have a potential application in practical dye pollutant treatment.

Phosphate removal from aqueous solution by Fe-La binary (hydr)oxides: A study of batch experiments and mechanisms

2021 ◽  
Author(s):  
Haijing Duan ◽  
Lin Zhang ◽  
Yu-long Wang ◽  
Yanhong Liu ◽  
Yangyang Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Ph Value ◽  
Phosphate Removal ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Batch Experiments ◽  
Exchange Reactions ◽  
X Ray ◽  
Co Precipitation

Abstract In this study, Fe-La binary (hydr)oxides were prepared by a co-precipitation method for phosphate removal. Various techniques, including secondary electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), powder X-ray diffraction (p-XRD) and Brunauer-Emmett-Teller (BET) surface area analysis, were employed to characterize the synthesized Fe-La binary (hydr)oxides. Batch experiments indicated that the performance of phosphate removal by Fe-La binary (hydr)oxides was excellent and increased with increasing La contents. The kinetics study showed that the adsorption was rapid and described better by the pseudo-second-order equation. The maximum adsorption capacities of Fe/La 3:1, Fe/La 1:1 and Fe/La 1:3 binary (hydr)oxides at pH 4.0 calculated by Langmuir model were 49.02, 69.44 and 136.99 mg/g, respectively. The uptake of phosphate was highly affected by solution pH and significantly reduced with the increase of pH value. The analyses of p-XRD, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) suggested that the predominant mechanisms of phosphate removal involved surface hydroxyl exchange reactions and co-precipitation of released La3+ and phosphate ions, which resulted into the formation of amorphous phase of rhabdophane (LaPO4∙0.5H2O). The results show great potential for the application on the treatment of phosphate decontamination for their high efficiency of phosphate removal.

Aluminate Green Phosphor with Small Particle Size Used for PDP via Co-Precipitation Method

2011 ◽  
Vol 295-297 ◽  
pp. 890-895
Author(s):  
Yan Dong ◽  
Yang Zhou ◽  
Xue Lin Han ◽  
Wei Jie Gu
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Small Particle ◽  
High Efficiency ◽  
Particle Growth ◽  
Solid State Reaction Method ◽  
Precipitation Method ◽  
Small Particle Size ◽  
Green Phosphor ◽  
Co Precipitation

Mg doped BaAl12O19:Mn2+ phosphor is one of the most efficient green phosphors for PDP. It is difficult to prepare the phosphor both have small particle size (< 3μm) and high luminescence. In the present work, a BaAl12O19:Mn2+ phosphor with small particle size was synthesized by the chemical co-precipitation method. Phase transformation and particle growth process during calcining process were investigated. The nucleation process was also discussed. The results show that, the phase transformation is complicated, the transition phases include BaCO3, γ-Al2O3, BaF2, BaAl2O4 and two phases contain Mn; The BaAl12O19 phase is formed from the reaction between BaAl2O4 phase and γ-Al2O3 phase, no a-Al2O3 phase appears during the entire process; The formation temperature of pure BaAl12O19 phase is 1200°C, which is lower than that in the high-temperature solid state reaction method. High efficiency BaAl12O19:Mn2+ phosphor with small particle size (< 2μm) and hexagonal flaky shape can be prepared by this method.

Moisture-resistant Nb-based fluoride K2NbF7:Mn4+ and oxyfluoride phosphor K3(NbOF5)(HF2):Mn4+: synthesis, improved luminescence performance and application in warm white LED

2021 ◽  
Author(s):  
Ge Pang ◽  
Feng Hong ◽  
Xiaoyi Liu ◽  
Yunxiao Zhang ◽  
Chunyan Zhang ◽  
...  
Keyword(s):  
Acid Solution ◽  
High Efficiency ◽  
Precipitation Method ◽  
White Led ◽  
Co Precipitation ◽  
Moisture Resistant ◽  
Luminescence Performance

Herein, high-efficiency Nb-based oxyfluoride K3(NbOF5)(HF2):Mn4+ and fluoride K2NbF7:Mn4+ phosphors were successfully synthesized using different amounts of HF acid solution by simple co-precipitation method. XRD, SEM and EDS were used to...

Catalytic Hydrolysis of Hydrogen Cyanide on Cu-Al Catalyst

2015 ◽  
Vol 1094 ◽  
pp. 15-19
Author(s):  
Lin Xia Yan ◽  
Sen Lin Tian ◽  
Qiu Lin Zhang
Keyword(s):  
Calcination Temperature ◽  
Hydrogen Cyanide ◽  
Influence Factor ◽  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Cu Content ◽  
Co Precipitation ◽  
The Impact ◽  
Hydrolysis Of

Cu-Al catalysts were synthesized by the co-precipitation method to study hydrolysis of hydrogen cyanide. During the synthesis, the impact of Cu/Al molar ratio, pH value and calcination temperature was investigated and the best synthesis condition was found. The results indicate that the remove of hydrogen cyanide first increases and then decreases with increasing Cu/Al molar ratio, pH value and calcination temperature, which reaches the maxima and remains above 95% at 360 min when Cu/Al molar ratio is 2:1, pH value is approximately 8.0 and calcination temperature is 400°C around. The analysis of X-ray diffraction (XRD) shows that Cu content is the main influence factor at Cu/Al molar ratio below 2:1 whereas crystallinity of catalysts is the key factor at Cu/Al molar ratio above 2:1.

High efficiency synthesis of Nd:YAG powder by a spray co-precipitation method for transparent ceramics

2018 ◽  
Vol 38 (5) ◽  
pp. 2454-2461 ◽  
Author(s):  
Wei Jing ◽  
Fang Li ◽  
Shengquan Yu ◽  
Xiangbo Ji ◽  
Tao Xu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Precipitation Method ◽  
Transparent Ceramics ◽  
Co Precipitation

Sonochemical Synthesis of Silica Coated Super Paramagnetic Iron Oxide Nanoparticles

2013 ◽  
Vol 756 ◽  
pp. 74-79 ◽  
Author(s):  
Bashiru Kayode Sodipo ◽  
Azlan Abdul Aziz
Keyword(s):  
Iron Oxide ◽  
Silica Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Ph Value ◽  
Superparamagnetic Iron Oxide ◽  
Silica Nanoparticle ◽  
Precipitation Method ◽  
Oxide Nanoparticles ◽  
Sonochemical Method ◽  
Co Precipitation

Superparamagnetic iron oxide nanoparticles (SPION) of sizes 5 to10 nm were synthesized by the co-precipitation method. They are coated with silica nanoparticles using sonication method. The SPION was produced under the optimum pH of 10, peptized in acidic medium and redispersed in water. The silica nanoparticles were produced through the Stöbermethod. Sonochemical coating of silica nanoparticle on the SPION was successfulat a pH value lower than 5. Otherwise, at higher pH value (but lower than point zero charge (PZC)), the SPION were found to be unstable. Fast hydrolysis of triethoxyvinylsilane(TEVS) shows that silica forms its own particles without coating onto the surfaces of the SPION. Under optimized experimental condition, sonochemical method of coating silica nanoparticles onto the SPION can be considered as an alternative for effective and prompt method that rely mainly on pH of the suspension.

Reactive Adsorption Desulfurization of Thiophene in n-hexane over Oxides Adsorbent of NiO-ZnO/Al2O3-SiO2

2013 ◽  
Vol 455 ◽  
pp. 43-47 ◽  
Author(s):  
Xiao Ming Hou ◽  
Ben Xian Shen ◽  
Ji Gang Zhao
Keyword(s):  
Reaction Time ◽  
Structural Properties ◽  
Reaction Temperature ◽  
Chemical Process ◽  
Removal Rate ◽  
Precipitation Method ◽  
Initial Concentration ◽  
Reactive Adsorption ◽  
Adsorption Desulfurization ◽  
Co Precipitation

The oxides adsorbent of NiO-ZnO/-Al2O3-SiO2 was prepared by co-precipitation method. SEM, XRD and BET studies were performed to understand the structural properties of the adsorbent. And the adsorbent can be used for the desulfurization of thiophene in n-hexane as model gasoline. Removal rate of thiophene increased with increasing reaction time. Removal rate of thiophene in equilibrium decreases with increasing the initial concentration of thiophene. The extent of adsorption in adsorbent increased with increasing the initial concentration of thiophene. The removal rate of thiophene increases with increasing reaction temperature, it showed that the desulfurization is a chemical process not a physical process.

Process Study on Green Treatment of Waste Anolyte

2014 ◽  
Vol 1015 ◽  
pp. 350-354
Author(s):  
Li Na Chen ◽  
Wan Yi Liu ◽  
Qi Lin Hu
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Chemical Precipitation ◽  
Environmental Benefits ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Waste Solution ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen

Contraposing the waste anolyte of industry, the paper proposed a new chemical precipitation method to recover Mn (II) ions and Mg (II) ions from the waste solution using ammonium hydrogen carbonate and ammonium dihydrogen phosphate as precipitants, respectively. The technological conditions of dealing procedure such as the molar ratio of reactants, pH value, reaction temperature and time, aging time were investigated. The results shown that the removal rate of Mn (II) ions and Mg (II) ions reached to 96 % and 98 %, and the yields of MnCO3 and NH4MgPO4·6H2O reached to 91 % and 94 %, respectively. The residual solution was recycled to realize the treatment greenly, which could meet the needs of production and increase environmental benefits.

Synthesis Conditions of Nano-Hydroxyapatite Using Chondroitin Sulfate by Co-Precipitation Method

2011 ◽  
Vol 236-238 ◽  
pp. 2076-2079
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Yong Huang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Chondroitin Sulfate ◽  
Ph Value ◽  
Orthogonal Design ◽  
Precipitation Method ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Co Precipitation

The introduction of biomineralization was coupled with the co-precipitation synthesis process of nano-hydroxyapatite with the addition of chondroitin sulfate as a template agent. The effect of a variety of processing conditions on the properties of final hydroxyapatite (HA) product was investigated by orthogonal design. The ratio of calcium to phosphorus was detected by chemical analysis, the phase composition was evaluated by X-ray diffraction (XRD), and the powder morphology was characterized by transmission electron microscope (TEM). The process scheme, moreover, was optimized by the analysis of four aspects which may have different extent of influence on product properties. It can be concluded from the results that product properties can be affected remarkably by the content of chondroitin sulfate and the pH value of reactant, less remarkably by the reaction temperature and slightly by the reaction time.

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