scholarly journals MnO2-loaded activated carbon and its adsorption of formaldehyde

BioResources ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 7193-7212 ◽  
Author(s):  
Liangcai Wang ◽  
Yishuang Wu ◽  
Shasha Liu ◽  
Yimeng Zhang ◽  
Yu Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Infrared Spectrometry ◽  
Adsorption Efficiency ◽  
X Ray Diffraction ◽  
Isothermal Model ◽  
X Ray ◽  
Preparation Conditions ◽  
The Stability ◽  
Coconut Shell Activated Carbon

Coconut shell activated carbon (AC) loaded with MnO2 was tested as an adsorbent for formaldehyde. Preparation conditions of MnO2-loaded AC (MnO2-AC) were optimized. The resulting AC and MnO2-AC were characterized by scanning electron microscopy, Brunauer-Emmet-Teller analysis, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and X-ray diffraction. The results showed that the adsorption efficiency of formaldehyde (3.5 mg/L) by MnO2-AC (concentration of manganese nitrate/sodium carbonate was 0.3 mol/L, impregnation oscillation time of 4 h, calcination temperature and time of 350 C and 4 h, respectively) was 93.1%, which increased by 251% compared to that of the AC. The adsorption equilibrium of MnO2-AC was achieved after 4 h. With increasing dosage of MnO2-AC, the rate of increasing of the adsorption efficiency became more gradual. The adsorption process of the formaldehyde solution with a low concentration fit the Langmuir adsorption isothermal model, where the adsorption capacity was 9.22 mg/g. The stability and regenerability of MnO2-AC were good.

Preparation of Pd/GO/Cu Electrode and Its Electrochemical Degradation for 2,4-Dichlorophenol

2020 ◽  
Vol 20 (6) ◽  
pp. 3604-3609
Author(s):  
Jian Zhang ◽  
Yuting Jiang ◽  
Bing Wang ◽  
Lanhe Zhang ◽  
Zheng Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Environment ◽  
Constant Current ◽  
Surface Element ◽  
Impregnation Method ◽  
Electrochemical Degradation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preparation Conditions ◽  
The Stability

Chlorinated aromatic compounds (CACs) are a class of persistent organic pollutants, which have serious damage to water environment due to their own stable structure. But a good many of CACs were abandoned because of their tremendous yields and wide applications, so it is urgent to find the effective degradation methods for CACs. The electrochemical method is supposed to be a simple, environmentally friendly and effective pathway to degrade CACs. In this paper, a Pd/GO/Cu composite electrode was prepared by a combination of impregnation method and constant current electrodeposition method, which showed good electrochemical degradation efficiency for the 2,4-dichlorophenol. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface structure, functional group composition, crystal structure and surface element valence of the electrode. Moreover, the stability of the electrode was investigated, and the preparation conditions of the electrode were optimized.

Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

1998 ◽  
Vol 76 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
I Coulthard ◽  
S Degen ◽  
Y -J Zhu ◽  
T K Sham
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gold Nanoclusters ◽  
Gold Complex ◽  
X Ray Diffraction ◽  
Complex Ions ◽  
X Ray ◽  
Preparation Conditions ◽  
P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

scholarly journals Biomass-Derived Activated Carbon as a Catalyst for the Effective Degradation of Rhodamine B dye

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 926
Author(s):  
Shamim Ahmed Hira ◽  
Mohammad Yusuf ◽  
Dicky Annas ◽  
Hu Shi Hui ◽  
Kang Hyun Park
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron

Activated carbon (AC) was fabricated from carrot waste using ZnCl2 as the activating agent and calcined at 700 °C for 2 h in a tube furnace. The as-synthesized AC was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis; the results revealed that it exhibited a high specific surface area and high porosity. Moreover, this material displayed superior catalytic activity for the degradation of toxic Rhodamine B (RhB) dye. Rate constant for the degradation of RhB was ascertained at different experimental conditions. Lastly, we used the Arrhenius equation and determined that the activation energy for the decomposition of RhB using AC was approximately 35.9 kJ mol−1, which was very low. Hopefully it will create a great platform for the degradation of other toxic dye in near future.

scholarly journals An Electrospun Preparation of the NC/GAP/Nano-LLM-105 Nanofiber and Its Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 854 ◽  
Author(s):  
Tingting Luo ◽  
Yi Wang ◽  
Hao Huang ◽  
Feifei Shang ◽  
Xiaolan Song
Keyword(s):  
Photoelectron Spectroscopy ◽  
Specific Impulse ◽  
Three Dimensional ◽  
Composite Fiber ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Chamber Temperature ◽  
Energetic Performance

In this work, an energetic composite fiber, in which 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) nanoparticles intimately incorporated with a nitrocellulose/glycidyl azide polymer (NC/GAP) fiber, was prepared by the electrospinning method. The morphology and structure of the nanofiber was characterized by scanning electron microscopy (SEM), energy dispersive X-Ray (EDX), fourier transform infrared spectroscopy (IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET). The nanofibers possessed a three-dimensional (3D) net structure and a large specific surface area. Thermal analysis, energetic performance, and sensitivities were investigated, and they were compared with NC/GAP and LLM-105 nanoparticles. The NC/GAP/nano-LLM-105 nanofibers show higher decomposition rates and lower decomposition temperatures. The NC/GAP/nano-LLM-105 decomposed to CO2, CO, H2O, N2O, and a few NO, -CH2O-, and -CH- fragments, in the thermal-infrared spectrometry online (TG-IR) measurement. The NC/GAP/nano-LLM-105 nanofibers demonstrated a higher standard specific impulse (Isp), a higher combustion chamber temperature (Tc), and a higher specialty height (H50). The introduction of nano-LLM-105 in the NC/GAP matrix results in an improvement in energetic performance and safety.

scholarly journals Investigation the Effects of Green-Synthesized Copper Nanoparticles on the Performance of Activated Carbon-Chitosan-Alginate for the Removal of Cr(VI) from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2617
Author(s):  
Inas A. Ahmed ◽  
Hala S. Hussein ◽  
Ahmed H. Ragab ◽  
Najla AlMasoud ◽  
Ayman A. Ghfar
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Contact Time ◽  
Sem Analysis ◽  
Adsorption Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chromium Vi ◽  
Transmission Electron ◽  
Freundlich Adsorption Isotherm

In the present investigation, green nano-zerovalent copper (GnZVCu), activated carbon (AC), chitosan (CS) and alginate (ALG) nanocomposites were produced and used for the elimination of chromium (VI) from a polluted solution. The nanocomposites GnZVCu/AC-CS-alginate and AC-CS-alginate were prepared. Analysis and characterization were performed by the following techniques: X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The SEM analysis revealed that the nanocomposites are extremely mesoporous, which leads to the greatest adsorption of Cr+6 (i.e., 97.5% and 95%) for GnZVCu/AC-CS-alginate and AC-CS-alginate, respectively. The adsorption efficiency was enhanced by coupling GnZVCu with AC-CS-alginate with a contact time of 40 min. The maximum elimination of Cr+6 with the two nanocomposites was achieved at pH 2. The isotherm model, Freundlich adsorption isotherm and kinetics model and P.S.O.R kinetic models were discovered to be better suited to describe the exclusion of Cr+6 by the nanocomposites. The results suggested that the synthesized nanocomposites are promising for the segregation of Cr+6 from polluted solutions, specially the GnZVCu/AC-CS-alginate nanocomposite.

scholarly journals FeCrAlloy Monoliths Coated with Ni/Al2O3 Applied to the Low-Temperature Production of Ethylene

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 291 ◽  
Author(s):  
Paula Brussino ◽  
Juan Bortolozzi ◽  
Oihane Sanz ◽  
Mario Montes ◽  
María Ulla ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Layer ◽  
X Ray Diffraction ◽  
Ethane Conversion ◽  
X Ray ◽  
Structured Catalyst ◽  
Temperature Programmed ◽  
Ni Species ◽  
The Stability ◽  
Geometric Surface

This paper investigates the oxidative dehydrogenation of ethane to produce ethylene at low temperatures (500 °C) in metallic structured substrates. To check this point, the FeCrAlloy® monoliths with different channel sizes (289–2360 cpsi) were prepared. The monoliths were coated with a Ni/Al2O3 catalyst (by washcoating of alumina and the latter nickel impregnation) and characterized by Scanning Electron Microscopy and Energy-Dispersive X-ray analysis (SEM-EDX), Temperature-Programmed Reduction (TPR), X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The catalytic results showed that all monoliths coated with ~300 mg of catalyst presented similar ethane conversion (15%) at 450 °C. However, the lowest selectivity to ethylene was found for the monolith with the lower channel size and the higher geometric surface area, where a heterogeneous catalyst layer with Ni enriched islands was generated. Therefore, it can be said that the selectivity to ethylene is linked to the distribution of Ni species on the support (alumina). Nevertheless, in all cases the selectivity was high (above 70%). On the other hand, the stability in reaction tests of one of the coated monoliths was done. This structured catalyst proved to be more stable under reaction conditions than the powder catalyst, with an initial slight drop in the first 8 h but after that, constant activity for the 152 h left.

scholarly journals Microwave heating oxidative stabilization of KMnO4 modified polyacrylonitrile-based carbon fiber precursor

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Jianhua Liu
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Photoelectron Spectroscopy ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Thermal Stabilization ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

Abstract Dielectric property, bulk density, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and mechanical properties were analyzed. PAN fibers (PFs) are polar materials, and the dielectric constant of KMnO4 modification fibers (Mn-PFs) is reduced. The bulk density of Mn-PFs under microwave stabilization (Mn-MSFs) is 0.04 g/cm3 higher than that of the microwave stabilized fibers (MSFs), shortening the value in one temperature zone. Compared with MSFs5, the stability of Mn-MSFs5 is improved by 10%, and the surface O content and O-containing functional groups are improved. The (002) crystal plane diffraction peak of Mn-MSFs5 is higher than that of MSFs5, and it has a higher stabilized structure. Moreover, after stabilization, the Mn element does not exist on the fiber surface and does not affect the structure of the stabilized fiber. The fineness of Mn-MSFs5 is 1.07 dtex, tensile strength is 1.52 cN/dtex, tensile modulus is 59.3 cN/dtex and elongation at break is 13.5%. It has excellent mechanical properties. In addition, a structural transformation of the thermal stabilization process is proposed, that is, the cyclization reaction first occurs, and then the dehydrogenation and oxidation reactions are performed.

scholarly journals Characterization of new adsorbent prepared from apricot stones activated carbon mixed with amorphous SiO2 from Algerian diatomite for removal of p-nitroaniline

2021 ◽  
pp. 73-88
Author(s):  
Hayet Tizi ◽  
Tarek Berrama ◽  
Djamila Hamane ◽  
Fatiha Ferrag-Siagh ◽  
Zoubida Bendjama
Keyword(s):  
Activated Carbon ◽  
Chemical Nature ◽  
Adsorption Efficiency ◽  
X Ray Diffraction ◽  
Amorphous Sio2 ◽  
X Ray ◽  
Porous Texture ◽  
Langmuir And Freundlich Models ◽  
Scanning Electron

This work aims to evaluate the adsorption efficiency of p-nitroaniline (PNA) onto apricot stones activated carbon (ASAC) mixed with treated extract of amorphous SiO2 (TEAS), prepared from Algerian diatomite (AD). The best removal percentage (85%) is obtained for a ratio ASAC/TEAS (1/1). Adsorbent characteristics are investigated by the Brunauer-Emmett-Teller (BET), the scanning electron microscope (SEM), infrared spectroscopy (IR), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The impregnation of TEAS and ASAC produces good adsorbent properties towards PNA especially in the ratio (1/1) and an increase in the specific surface. The isotherm data are well fitted by the Langmuir and Freundlich models. The maximum PNA uptake obtained is 94.34 mg g-1. The performances of ASAC/TEAS for the PNA adsorption were compared with some adsorbents previously studied for the same purpose, and results show that the composite in the present work exhibit better performances. The adsorption behavior of the concerned material is explained on the basis of its chemical nature and porous texture.

Growth and Characterization of Thermal Oxides on Gallium Nitride

1997 ◽  
Vol 468 ◽  
Author(s):  
Scott D. Wolter ◽  
Suzanne E. Mohney ◽  
Hari Venugopalan ◽  
Debra L. Waltemyer ◽  
Brian P. Luther
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxide Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Air ◽  
High Temperature Electronics ◽  
Rate Limiting Step ◽  
Thermal Oxide ◽  
Device Applications ◽  
The Stability

ABSTRACTLittle information is available about the thermal oxidation of GaN. Since GaN is of interest for high temperature electronics, knowledge of the stability of GaN in potentially oxidizing environments would be useful. Furthermore, evaluation of the characteristics of the thermal oxide will provide information needed for assessing the potential of this oxide in processing or device applications.In this study, thick GaN epilayers and GaN powders were exposed to dry air at 450°C, 750°C, 900°C, 925°C, 950°C, and 1000°C for periods of 1 to 25 hours. Following oxidation, the epilayers were analyzed by x-ray photoelectron spectroscopy and glancing incidence x-ray diffraction, and the powders were analyzed by conventional x-ray diffraction. For both the GaN films and powders, significant oxidation was observed at 900°C, and the oxide was identified as monoclinic β-Ga2O3. Oxidation in dry air resulted in roughening of the oxide/GaN interface and oxide surface. In the temperature range 900°C to 1000°C, linear kinetics were observed for times up to 10 hours indicating an interfacial reaction mechanism as the rate limiting step for oxidation. An apparent activation energy of ∼72 kcal/mole was determined for this process.

Phase Transformation of Cu-Mo-C Powder during Mechanical Alloying and Annealing Process

2011 ◽  
Vol 233-235 ◽  
pp. 1678-1683
Author(s):  
Ke Sheng Zuo ◽  
Sheng Qi Xi ◽  
Jing En Zhou
Keyword(s):  
Phase Transformation ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Graphite Powder ◽  
High Energy ◽  
Milling Process ◽  
Carbon Powder ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray

The allotropes of graphite and activated carbon were mixed with Cu and Mo powder, respectively. And the two groups of mixtures were high-energy milled and annealed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and DSC/TG were used to investigate the phase transformation during the milling and sintering process. For both groups of powder milled, Mo was hard to dissolve in Cu, and C mainly congregated in the surface of Cu powder. When Cu-Mo-graphite powder as milled was annealed, Mo2C was formed. In comparison to Cu-Mo-graphite alloyed powder, Cu-Mo-activated carbon powder partially formed Cu oxide and Mo oxide with higher binding energy during milling process, which caused higher reduction temperature of Cu oxide and reaction temperature of Mo2C.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

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