scholarly journals Influence of addition of KOH on the yield and characteristics of humic acids extracted from lignite using NaOH

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yaxing Li ◽  
Shenfu Yuan
Keyword(s):  
Functional Groups ◽  
Humic Acids ◽  
Potassium Hydroxide ◽  
Maximum Yield ◽  
Extraction Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Naoh Solution ◽  
Proximate And Ultimate Analysis

AbstractIn this study, humic acids (HAs) were extracted from Chinese lignite by adding KOH to a NaOH solution. The extraction yield of HAs was found to improve because of the synergistic effect imparted by the alkali mixture of sodium hydroxide (NaOH) and potassium hydroxide (KOH). The maximum yield was obtained at 150 min by adding the mixture of 0.750 M NaOH + 0.710 M KOH to Xianfeng lignite at 80 °C. The potassium (K), sodium (Na), nitrogen (N), oxygen (O), and iron (Fe) contents were determined by X-ray diffraction, scanning electron microscopy, and proximate and ultimate analysis. The oxygen-containing functional groups in HAs were identified by Fourier transform infrared spectroscopy. The addition of KOH resulted in higher oxygen/carbon and nitrogen/carbon ratios and oxygen-containing functional groups, as compared with that in NaOH alone. The extractants containing KOH could release HAs with a higher proportion of K, Fe, N contents, which is beneficial for HAs fertilizers prepared from the lignite. The release of the nutrients (K, Fe, N) which are essential for the crops is determined by the KOH dosages.

Effect of Yttria-Stabilized Zirconia Concentration in an Electroless Bath on Microstructure and Composition of Ni/Yttria-Stabilized Zirconia Nanocomposite

2021 ◽  
Vol 21 (11) ◽  
pp. 5592-5602
Author(s):  
Samira Almasi ◽  
Ali Mohammad Rashidi
Keyword(s):  
High Performance ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Nickel Ion ◽  
Nanocomposite Particles ◽  
X Ray ◽  
Ni Content ◽  
Naoh Solution ◽  
Average Size

The effect of the yttria-stabilized zirconia (YSZ) nanoparticle loading in an electro-less bath was considered as one of the vital synthesis variables for control Ni content and microstructure of prepared nanocomposite particles, which are two crucial factors to achieving high-performance SOFC anode. Nanocomposite particles were prepared using a simple electroless method without any expensive pretreatment of sensitizing by Sn2+ ions as well as activating by Pd2+ ions that are usually used to apply nickel coating on the surface of a non-conductive substrate. The process was performed by adding YSZ nanoparticles into NaOH solution, separating them from the solution by the centrifugal method, then providing several water-based nanofluids with different concentrations of activated YSZ nanoparticles, mixing them with NiCI2 solution, followed by adding the hydrazine and then NaOH solution. X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis were used to analyze the prepared nanocomposite particles. It is observed that after adding YSZ nanoparticles into the NaOH solution, the pH of the solution varied gradually from a starting pH of 10.2 to 9. Also, by increasing the YSZ nanoparticles loading in the electroless bath from 76 mg/l to 126 mg/l, the grain size of Ni deposits, the Ni content and the average size of the prepared nanocomposite particles decreased. The electrochemical mechanism previously proposed for the nickel ion reduction was modified, and a novel analytical model was proposed for variation of the efficiency of Ni deposition with YSZ nanoparticles loading.

Study on the Oxidation and Spontaneous Combustion Characteristics of Jurassic Coal in North Shaanxi

2014 ◽  
Vol 977 ◽  
pp. 124-128 ◽  
Author(s):  
Jun Deng ◽  
Kai Wang ◽  
Xiao Wei Zhai
Keyword(s):  
Functional Groups ◽  
Spontaneous Combustion ◽  
Combustion Process ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
High Oxygen Content ◽  
Ether Oxygen ◽  
Jurassic Coal ◽  
Proximate And Ultimate Analysis ◽  
Low Sulfur

Proximate and ultimate analysis, X-ray diffraction, infrared spectroscopy and thermal analysis experiments were carried out to study the spontaneous combustion oxidation based characteristic of six Jurassic coal samples from North Shaanxi in West China and three Permo-carboniferous coal samples from East China. The results showed that the characteristic of north Shaanxi Jurassic coal was low ash, low sulfur, high volatile, high oxygen content and amorphous structure. More type and quantity of reactive functional groups existed in the original Jurassic coal, such as carboxyl, methyl, methylene and ether oxygen. And the characteristic temperatures of north Shaanxi Jurassic coal sample in the oxidation and spontaneous combustion process was lower than other coal samples, due to the participation in the reaction with oxygen of the more active functional groups.

A new stacking variant of Na2Pt(OH)6

2018 ◽  
Vol 73 (11) ◽  
pp. 831-836 ◽  
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Oxygen Pressure ◽  
Title Compound ◽  
Structure Type ◽  
Direct Reaction ◽  
Solid Residue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edge Distance ◽  
Naoh Solution

AbstractA new stacking variant of sodium hexa-hydroxo platinate(IV), Na2Pt(OH)6, was synthesized and its structure elucidated through X-ray diffraction. The new polymorph was prepared by direct reaction of PtO2 with an excess of NaOH solution applying elevated oxygen pressure at 300°C. The structure consists of layers of edge sharing Pt(OH)6 and Na(OH)6 octahedra. These layers are separated by an edge-to-edge distance of ~2.4 Å. The packing of the hydroxide ions corresponds to the hcp sequence, the title compound thus may be regarded a cation ordered variant of the Brucite structure type. During heating above T~300°C all constitutional water is released, and anhydrous Na2PtO3 remains as the solid residue.

Effect of Cathode Waste Material Concentration in Conductive Paint Coating

2021 ◽  
Vol 4 (2) ◽  
pp. 78-81
Author(s):  
N.S.W. Zulkefeli ◽  
W.M.I.W. Ismail ◽  
M.K.A.A. Razab ◽  
M.N. Masri
Keyword(s):  
Electromagnetic Interference ◽  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Waste Material ◽  
X Ray Diffraction ◽  
Paint Coating ◽  
X Ray ◽  
Electronic Application ◽  
Before And After ◽  
Conductive Paint

The conductive paint coating can be used to control the electromagnetic interference in electronic application. Conductive paint coating was made by mixing the epoxy and hardener with cathode waste material (CWM) in order to manipulate their properties. In this study, the conductivity and the thickness of the paint has been studied. The thickness of conductive paint coating was depends on the agglomeration of CWM content. The increasing of wt% of CWM, the thickness of paint is increasing. Bruker D2Phaser X-Ray diffraction has been used in order to get the phase analysis of the paint before and after soaking into Potassium Hydroxide solution

CoO-Co2P composite nanosheets as highly active catalysts for sodium borohydride hydrolysis to generate hydrogen

2020 ◽  
Vol 13 (06) ◽  
pp. 2051025
Author(s):  
Hongyan Liu ◽  
Qianyu Shi ◽  
Yumei Yang ◽  
Ya-Na Yu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Sodium Borohydride ◽  
Hydrogen Generation ◽  
Sodium Hypophosphite ◽  
X Ray Diffraction ◽  
Water Displacement ◽  
X Ray ◽  
Highly Active ◽  
Naoh Solution ◽  
Adsorption Desorption ◽  
Hydrolysis Of

In this paper, CoO[Formula: see text]Co2P composite nanocatalysts as highly active catalysts were successfully prepared for catalytic hydrolysis of sodium borohydride (NaBH[Formula: see text] to generate hydrogen. For catalyst preparation, pre-synthesized Co(OH)2 nanosheets were uniformly mixed with sodium hypophosphite (NaH2PO[Formula: see text] and then treated through vapor-phase phosphorization process. For characterization, field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), N2 adsorption–desorption measurement and X-ray photoelectric spectroscopy (XPS) were carried out, and traditional water-displacement method was performed to measure the hydrogen generation rate (HGR). It was found that component and catalytic activity of the composites were greatly affected by the ratio of Co(OH)2 to NaH2PO2. When the ratio was 2:1, the obtained catalyst composed of CoO and Co2P presented the highest HGR up to 3.94[Formula: see text]L min[Formula: see text] g[Formula: see text] using a 2[Formula: see text]wt.% NaBH[Formula: see text][Formula: see text]wt.% NaOH solution at [Formula: see text]C, and the apparent activation energy was detected as low as 27.4[Formula: see text]kJ mol[Formula: see text]. Additionally, the optimum CoO[Formula: see text]Co2P catalyst still retains 60% of the initial activity after recycling four times.

scholarly journals Improving Linear Range Limitation of Non-Enzymatic Glucose Sensor by OH− Concentration

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 186
Author(s):  
Lory Wenjuan Yang ◽  
Elton Enchong Liu ◽  
Alex Fan Xu ◽  
Jason Yuanzhe Chen ◽  
Ryan Taoran Wang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Glucose Oxidation ◽  
Glucose Sensor ◽  
Linear Range ◽  
Diabetic Patients ◽  
Current Response ◽  
Effective Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naoh Solution

The linear range of the non-enzymatic glucose sensor is usually much smaller than the glucose level of diabetic patients, calling for an effective solution. Despite many previous attempts, none have solved the problem. Such a challenge has now been conquered by raising the NaOH concentration in the electrolyte, where amperometry, X-ray diffraction, Fourier-transform infrared spectroscopy, and Nuclear magnetic resonance measurements have been conducted. The linear range has been successfully enhanced to 40 mM in 1000 mM NaOH solution, and it was also found that NaOH affected the degree of glucose oxidation, which influenced the current response during sensing. It was expected that the alkaline concentration must be 25 times higher than the glucose concentration to enhance the linear range, much contrary to prior understanding.

Study on Magnetic Properties of Na-Doped rGO Prepared from Coconut Shells

2020 ◽  
Vol 855 ◽  
pp. 160-165
Author(s):  
Deril Ristiani ◽  
Niken Sylvia Puspitasari ◽  
Retno Asih ◽  
Fahmi Astuti ◽  
Malik Anjelh Baqiya ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene ◽  
Naoh Solution ◽  
Na Ions ◽  
Diffraction Peaks ◽  
Coconut Shells

Na-doped reduced graphene oxide (Na-rGO) was prepared by wet mixing process of the reduced graphene oxide (rGO) in NaOH solution. The results showed that the rGO doped with Na ions can increase its magnetization approximately 2 times greater than that in rGO without doping. Saturation magnetization (Ms) for rGO and Na-rGO samples are 0.017 emu/g and 0.037 emu/g, respectively. The increasing value of magnetization is suggested to be due to defect presented in the Na-rGO samples. Both samples, rGO and Na-rGO, have the similar XRD (X-ray Diffraction) spectra that is marked by two characteristic diffraction peaks of rGO, which are associated with [002] and [10] planes, followed by the increasing inter-planar distance in Na-rGO samples which might be due to Na ions intercalation into rGO sheets, confirmed by the energy-dispersive X-ray (EDX) result revealing the presence of Na atoms in rGO.

scholarly journals Structural Characterization of Graphene Oxide: Surface Functional Groups and Fractionated Oxidative Debris

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1180 ◽  
Author(s):  
Elvin Aliyev ◽  
Volkan Filiz ◽  
Muntazim M. Khan ◽  
Young Joo Lee ◽  
Clarissa Abetz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Functional Groups ◽  
Structural Model ◽  
Oxide Surface ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Surface Functional Groups ◽  
X Ray ◽  
Transmission Electron

The purpose of this work is the structural analysis of graphene oxide (GO) and by means of a new structural model to answer the questions arising from the Lerf–Klinowski and the Lee structural models. Surface functional groups of GO layers and the oxidative debris (OD) stacked on them were investigated after OD was extracted. Analysis was performed successfully using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), X-ray photoemission spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, solid-state nuclear magnetic resonance spectroscopy (SSNMR), standardized Boehm potentiometric titration analysis, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The analysis showed that graphene oxide layers, as well as oxidative debris contain different functional groups such as phenolic –OH, ketone, lactone, carboxyl, quinone and epoxy. Based on these results, a new structural model for GO layers is proposed, which covers all spectroscopic data and explains the presence of the other oxygen functionalities besides carboxyl, phenolic –OH and epoxy groups.

Synthesis of Carbon Nanosphere at Low Temperatures Based on Bamboo Fiber

2019 ◽  
Vol 966 ◽  
pp. 163-168 ◽  
Author(s):  
Yulia Kirana Lahsmin ◽  
Dahlang Tahir ◽  
Bualkar Abdullah ◽  
Sultan Ilyas ◽  
Inayatul Mutmainna
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperatures ◽  
Potassium Hydroxide ◽  
Bamboo Fiber ◽  
X Ray Diffraction ◽  
Activation Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Bamboo Fibers

Carbon Nanosphere (CNs) has been successfully synthesized from bamboo fibers at low temperatures by carbonization and activation. For activation used Potassium Hydroxide (KOH) at temperature 105°C, 155°C, 205°C, 255°C and 305°C. X-Ray Diffraction (XRD) spectra shows hexagonal and amorphous phase and Fourier Transform Infrared (FTIR) spectra shows decrease C-O bond with increasing activation temperature. Transmission Electron Microscopy (TEM) image for activation temperature of 105°C confirmed that sources the formation of Carbon Nanosphere. In this study shows bamboo fiber has a high potential as a carbon nanosphere material.

Synthesis of Biodiesel from Castor Oil Catalyzed by Cesium Phosphotungstate with the Assistance of Microwave

2013 ◽  
Vol 291-294 ◽  
pp. 300-306 ◽  
Author(s):  
Hong Yuan ◽  
Qing Shu
Keyword(s):  
Microwave Radiation ◽  
Castor Oil ◽  
Solid Acid ◽  
Maximum Yield ◽  
Conventional Heating ◽  
Molar Ratio ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed

Two cesium phosphotungstate-derived solid acid catalysts (Cs2.5H0.5PW12 and Cs0.5H2.5PW12) were prepared. The resulting catalysts were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption and desorption isotherm and temperature programmed desorption of ammonia(NH3-TPD). The Cs2.5H0.5PW12 and Cs0.5H2.5PW12 were respectively used to catalyze the tranesterification of castor oil and methanol for the synthesis of biodiesel with the assistance of microwave. Results shown microwave radiation can greatly enhance the transesterification process when compared with conventional heating method. Cs2.5H0.5PW12 showed better catalyst performance than Cs0.5H2.5PW12. A maximum yield of 90% was obtained from the using of 30:1 molar ratio of methanol to castor oil and 15 wt % mass ratio of catalyst to castor oil at 343 K under microwave radiation after 4h.

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