scholarly journals Surface Properties of Halloysite-Carbon Nanocomposites and Their Application for Adsorption of Paracetamol

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5647
Author(s):  
Beata Szczepanik ◽  
Dariusz Banaś ◽  
Aldona Kubala-Kukuś ◽  
Karol Szary ◽  
Piotr Słomkiewicz ◽  
...  
Keyword(s):  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Adsorption Model ◽  
Xps Spectra ◽  
Carbon Nanocomposites ◽  
Wide Range ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Energy Survey ◽  
Photoelectron Peak

Analysis of surface properties of halloysite-carbon nanocomposites and non-modified halloysite was carried out with surface sensitive X-ray photoelectron spectroscopy (XPS) and inverse gas chromatography (IGC). The XPS spectra were measured in a wide range of the electron binding energy (survey spectra) and in the region of C 1s photoelectron peak (narrow scans). The IGC results show the changes of halloysite surface from basic for pure halloysite to acidic for carbon-halloysite nanocomposites. Halloysite-carbon nanocomposites were used as adsorbents of paracetamol from an aqueous solution. The adsorption mechanism was found to follow the pseudo-second-order and intra-particle diffusion models. The Langmuir multi-center adsorption model described well the obtained experimental data. The presence of carbon increased significantly the adsorption ability of halloysite-carbon nanocomposites for paracetamol in comparison to the non-modified halloysite.

Preparation and Pretreatment Effects on Co/SiO2 Catalysts for Fischer-Tropsch Synthesis

1994 ◽  
Vol 368 ◽  
Author(s):  
Kent E. Coulter ◽  
Allen G. Sault
Keyword(s):  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Cobalt Catalysts ◽  
Volatile Components ◽  
Cobalt Metal ◽  
Nitrate Hexahydrate ◽  
Incipient Wetness Impregnation ◽  
Supported Metal Catalysts ◽  
Drying Procedures ◽  
Wide Range

ABSTRACTCatalyst drying procedures are often given little attention in the experimental section of papers on supported metal catalysts. In general, drying appears to be regarded as a method to remove water and other volatile components prior to calcining or reduction, but not as a method to affect the surface properties of the catalyst. This study uses x-ray photoelectron spectroscopy (XPS) to examine the surface properties of silica supported cobalt catalysts, prepared using incipient wetness impregnation of cobalt nitrate hexahydrate, and finds a wide range of cobalt distributions, extent of nitrate decomposition, and reducibility for various drying procedures. After UHV annealing and subsequent reduction, the final cobalt surface properties are found to depend on the length of heating and the environment during the drying process. Maximum cobalt metal surface area is obtained for samples exposed to limited amounts of air and dried under conditions where gas phase species generated during the precursor decomposition are rapidly removed from the surface of the sample.

scholarly journals Involute the reactivity of persulfate with zero-valent iron for enhanced removal of arsenic (V) in aspect involvement of Fe2+ or Fe3+

2019 ◽  
Vol 80 (6) ◽  
pp. 1031-1041
Author(s):  
Yue Wang ◽  
Tianying Chang ◽  
Zhengchao Zhang ◽  
Kaijie Pei ◽  
Jie Fu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sewage Treatment ◽  
Industrial Effluents ◽  
Ferrous Ions ◽  
Metals Removal ◽  
Wide Range ◽  
Pseudo Second Order ◽  
Timely Fashion ◽  
Co Precipitation ◽  
Removal Of Arsenic

Abstract Being a fundamental issue regarding sewage treatment, heavy metals removal from industrial effluents has been subject to intense scrutiny in both the academic and practical worlds. The removal of pentavalent arsenic (As(V)), one of the most poisonous pollutants, was investigated using a sodium persulfate and iron powder system activated by ferrous ions (Fe2+-ZVI-PS). As(V) could be effectively removed by an Fe2+-ZVI-PS system in a timely fashion (minute scale) with high removal rates (more than 90.0%) over a wide range of pH (1–9) and concentration (20–100 mg/L). The removal of As(V) by the Fe2+-ZVI-PS system integrated favorably with the pseudo-second-order reaction kinetics. Researches on X-ray photoelectron spectroscopy (XPS) demonstrated that the Fe2+-ZVI-PS system enables the removal of As(V) through the process of co-precipitation and adsorption. Our findings thus emphasized that the Fe2+-ZVI-PS system should be an effective trigger to purifying arsenic from the environment. Our results indicated that the Fe2+-ZVI-PS system could be an effective candidate for remediation of arsenic in the environment.

scholarly journals in Situ X-ray Photoelectron Spectroscopic and Electrochemical Studies of the Bromide Anions Dissolved in 1-Ethyl-3-Methyl Imidazolium Tetrafluoroborate

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 304 ◽  
Author(s):  
Jaanus Kruusma ◽  
Arvo Tõnisoo ◽  
Rainer Pärna ◽  
Ergo Nõmmiste ◽  
Enn Lust
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Residual Water ◽  
Carbon Electrode ◽  
Xps Spectra ◽  
X Ray ◽  
In Situ Xps ◽  
Vacuum Interface ◽  
Photoelectron Peak

Influence of electrode potential on the electrochemical behavior of a 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) solution containing 5 wt % 1-ethyl-3-methylimidazolium bromide (EMImBr) has been investigated using electrochemical and synchrotron-initiated high-resolution in situ X-ray photoelectron spectroscopy (XPS) methods. Observation of the Br 3d5/2 in situ XPS signal, collected in a 5 wt % EMImBr solution at an EMImBF4–vacuum interface, enabled the detection of the start of the electrooxidation process of the Br- anion to Br3- anion and thereafter to the Br2 at the micro-mesoporous carbon electrode, polarized continuously at the high fixed positive potentials. A new photoelectron peak, corresponding to B–O bond formation in the B 1s in situ XPS spectra at E ≤ –1.17 V, parallel to the start of the electroreduction of the residual water at the micro-mesoporous carbon electrode, was observed and is discussed. The electroreduction of the residual water caused a reduction in the absolute value of binding energy vs. potential plot slope twice to ca. dBE dE-1 = –0.5 eV V-1 at E ≤ –1.17 V for C 1s, N 1s, B 1s, F 1s, and Br 3d5/2 photoelectrons.

scholarly journals Effect of Bio-Based Surfactant on Wettability of Low-Rank Coal Surface and Its Mechanism

2021 ◽  
Author(s):  
Lin Li ◽  
Mingpu Liu ◽  
Jianqiao Lvu ◽  
Xiaoteng Li ◽  
Zhihao Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water System ◽  
Low Rank ◽  
Order Kinetic ◽  
Low Rank Coal ◽  
Adsorption Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
The Stability ◽  
Adhesion Work

Abstract In this study, the effect of a bio-based environment-friendly surfactant, cardanol polyoxyethylene ether (BGF), on the wettability of the surface of low-rank coal (LRC) and its mechanism were studied. The adsorption experiment showed that the adsorption of the surfactant conformed to the Langmuir adsorption model and the pseudo-second-order kinetic model. The adsorption was mainly affected by hydrogen bonding, and the adsorption rate was affected by intraparticle diffusion and liquid film diffusion. The wettability experiment showed that the influence of BGF on the wettability of the surface of LRC followed the given order: BGF-7 > BGF-10 > BGF-15. The investigation of adhesion work showed that the adhesion work and the stability of the coal–water system decreased after adsorption. Fourier transform infrared and X-ray photoelectron spectroscopy analyses showed that after adsorption, the peak strength of vinyl ether, the content of elemental carbon, and the content of C-C/C-H groups increased.

scholarly journals The Characterization and Amoxicillin Adsorption Activity of Mesopore CaCO3 Microparticles Prepared Using Rape Flower Pollen

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 254 ◽  
Author(s):  
Lvshan Zhou ◽  
Tongjiang Peng ◽  
Hongjuan Sun ◽  
Xiaogang Guo ◽  
Dong Fu
Keyword(s):  
Second Order ◽  
Equilibrium Adsorption ◽  
Isotherm Models ◽  
Precipitation Reaction ◽  
Adsorption Model ◽  
Diffusion Kinetic ◽  
Adsorption Activity ◽  
Adsorption Isotherm Models ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

A precipitation reaction method was employed to prepare mesopore calcium carbonate (CaCO3) using rape flower pollen as the template. CaCO3 adsorbent was characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Brunner−Emmet−Teller measurements (BET). The equilibrium adsorption data on amoxicillin were explained using Langmuir, Freundlich, and Temkin adsorption isotherm models. The pseudo-first order, second order, pseudo-second order, and intra-particle diffusion kinetic models were used to explore adsorption kinetics. Equilibrium adsorption of as-prepared CaCO3 was better depicted using the Langmuir adsorption model with an R2 of 0.9948. The separation factor (RL) was found to be in the range of 0 < RL < 1, indicating the favorable adsorption of amoxicillin. The adsorption capacity of mesopore CaCO3 reached 13.49 mg·g−1 in 0.2 g∙L−1 amoxicillin solution. The values of adsorption thermodynamic parameters (ΔHθ, ΔSθ, ΔGθ) were obtained. In addition, the adsorption process turned out to be endothermic and spontaneous for the CaCO3 product at 298 K, 308 K, and 318 K.

scholarly journals Novel, Environment-Friendly Cellulose-Based Derivatives for Tetraconazole Removal from Aqueous Solution

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 450
Author(s):  
Bayan Khalaf ◽  
Othman Hamed ◽  
Shehdeh Jodeh ◽  
Ghadir Hanbali ◽  
Roland Bol ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Adsorption Enthalpy ◽  
Environment Friendly ◽  
Carbonyl Chloride ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

In this study, cellulose-based derivatives with heterocyclic moieties were synthesized by reacting cellulose with furan-2-carbonyl chloride (Cell-F) and pyridine-2,6-dicarbonyl dichloride (Cell-P). The derivatives were evaluated as adsorbents for the pesticide tetraconazole from aqueous solution. The prepared adsorbents were characterized by SEM, TGA, IR, and H1 NMR instruments. To maximize the adsorption efficiency of tetraconazole, the optimum conditions of contact time, pH, temperature, adsorbent dose, and initial concentration of adsorbate were determined. The highest removal percentage of tetraconazole from water was 98.51% and 95% using Cell-F and Cell-P, respectively. Underivatized nanocellulose was also evaluated as an adsorbent for tetraconazole for comparison purpose, and it showed a removal efficiency of about 91.73%. The best equilibrium adsorption isotherm model of each process was investigated based on the experimental and calculated R2 values of Freundlich and Langmuir models. The adsorption kinetics were also investigated using pseudo-first-order, pseudo-second-order, and intra-particle-diffusion adsorption kinetic models. The Van’t Hoff plot was also studied for each adsorption to determine the changes in adsorption enthalpy (∆H), Gibbs free energy (∆G), and entropy (∆S). The obtained results showed that adsorption by Cell-F and Cell-P follow the Langmuir adsorption isotherm and the mechanism follows the pseudo-second-order kinetic adsorption model. The obtained negative values of the thermodynamic parameter ∆G (−4.693, −4.792, −5.549 kJ) for nanocellulose, Cell-F, and Cell-P, respectively, indicate a spontaneous adsorption process. Cell-F and Cell-P could be promising absorbents on a commercial scale for tetraconazole and other pesticides.

scholarly journals Designing Phenyl Porous Organic Polymers with High-Efficiency Tetracycline Adsorption Capacity and Wide pH Adaptability

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 203
Author(s):  
Wenjie Nie ◽  
Jiao Liu ◽  
Xue Bai ◽  
Zefeng Xing ◽  
Ying Gao
Keyword(s):  
Adsorption Capacity ◽  
High Efficiency ◽  
Organic Polymer ◽  
Maximum Adsorption Capacity ◽  
Organic Polymers ◽  
Adsorption Model ◽  
Porous Organic Polymers ◽  
One Pot ◽  
Wide Range ◽  
Pseudo Second Order

Adsorption is an effective method to remove tetracycline (TC) from water, and developing efficient and environment-friendly adsorbents is an interesting topic. Herein, a series of novel phenyl porous organic polymers (P-POPs), synthesized by one-pot polymerization of different ratios of biphenyl and triphenylbenzene under AlCl3 catalysis in CH2Cl2, was studied as a highly efficient adsorbent to removal of TC in water. Notably, the obtained POPs possessed abundant phenyl-containing functional groups, large specific surface area (1098 m2/g) with abundant microporous structure, high pore volume (0.579 cm3/g), favoring the removal of TC molecules. The maximum adsorption capacity (fitted by the Sips model) could achieve 581 mg/g, and the adsorption equilibrium is completed quickly within 1 h while obtaining excellent removal efficiency (98%). The TC adsorption process obeyed pseudo-second-order kinetics and fitted the Sips adsorption model well. Moreover, the adsorption of POPs to TC exhibited a wide range of pH (2–10) adaptability and outstanding reusability, which could be reused at least 5 times without significant changes in structure and efficiency. These results lay a theoretical foundation for the application of porous organic polymer adsorbents in antibiotic wastewater treatment.

scholarly journals Tannin-based biosorbent encapsulated into calcium alginate beads for Cr(VI) removal

2020 ◽  
Vol 81 (5) ◽  
pp. 936-948 ◽  
Author(s):  
Xubing Sun ◽  
Jiayong Zhang ◽  
Guowen Ding ◽  
Yaohui You
Keyword(s):  
Photoelectron Spectroscopy ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Formaldehyde Resin ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intra Particle Diffusion ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Low Toxicity

Abstract A composite biosorbent (AC-TFR) prepared by encapsulating tannin-formaldehyde resin (TFR) into calcium alginate (AC) beads was used to remove Cr(VI) from an aqueous solution. Various influencing factors, such as TFR dosage, pH, initial Cr(VI) concentration, contact time, temperature and presence of co-ions in the medium, were investigated. The structures and adsorption performances of the adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Compared with other AC-TFR adsorbents, AC-TFR-2 (mass ratio of AC:TFR = 1:1) showed an excellent adsorption capacity based on the efficiency of Cr(VI) removal. The kinetic data fitted to pseudo-second-order and intra-particle diffusion models suggested that the adsorption process was subject to a rate-controlling step. The equilibrium adsorption data fitted well to the Langmuir isotherm model, and the maximum adsorption capacities of AC-TFR-2 were 145.99, 167.22 and 174.52 mg/g at 288, 298, and 308 K, respectively. The thermodynamic parameters revealed that Cr(VI) removal by AC-TFR-2 was endothermic and spontaneous, and the process was chemical adsorption. The mechanism of Cr(VI) removal consisted first of reduction to Cr(III), which has a low toxicity, and then chelation onto AC-TFR-2 via ion exchange.

scholarly journals Synthesis and Characterization of Halloysite/Carbon Nanocomposites for Enhanced NSAIDs Adsorption from Water

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3754 ◽  
Author(s):  
Beata Szczepanik ◽  
Nina Rędzia ◽  
Laura Frydel ◽  
Piotr Słomkiewicz ◽  
Anna Kołbus ◽  
...  
Keyword(s):  
Density Functional ◽  
Structural Changes ◽  
Adsorption Mechanism ◽  
Nitrogen Adsorption ◽  
Infrared Spectrometry ◽  
Adsorption Model ◽  
Adsorption Method ◽  
Carbon Nanocomposites ◽  
Chemical Structures ◽  
Intra Particle Diffusion

The adsorption of ketoprofen, naproxen, and diclofenac (non-steroidal anti-inflammatory drugs, NSAIDs) on halloysite/carbon nanocomposites and non-modified halloysite were investigated in this work. Halloysite/carbon nanocomposites were obtained through liquid phase impregnation and carbonization using halloysite as the template and saccharose as the carbon precursor. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and low-temperature nitrogen adsorption method were employed to study the morphological and structural changes of the halloysite/carbon nanocomposites. The effects of contact time, initial concentration of adsorbates, pH of solution, and mass of adsorbent on the adsorption were studied. Adsorption mechanism was found to fit pseudo-second-order and intra-particle diffusion models. The obtained experimental adsorption data were well represented by the Langmuir multi-center adsorption model. Adsorption ability of halloysite/carbon nanocomposites was much higher for all the studied NSAIDs in comparison to non-modified halloysite. Optimized chemical structures of ketoprofen, naproxen, and diclofenac obtained by Density Functional Theory (DFT) calculation showed that charge distributions of these adsorbate molecules and their ions can be helpful to explain the details of adsorption mechanism of NSAIDs on halloysite/carbon nanocomposites.

scholarly journals Gold–Carbon Nanocomposites for Environmental Contaminant Sensing

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 719
Author(s):  
Shahrooz Rahmati ◽  
William Doherty ◽  
Arman Amani Babadi ◽  
Muhamad Syamim Akmal Che Mansor ◽  
Nurhidayatullaili Muhd Julkapli ◽  
...  
Keyword(s):  
Environmental Pollutants ◽  
High Sensitivity ◽  
Environmental Crisis ◽  
World Population ◽  
Chemical Contaminants ◽  
Carbon Nanocomposites ◽  
Minimal Sample ◽  
Wide Range ◽  
And Control ◽  
Analytical Tools

The environmental crisis, due to the rapid growth of the world population and globalisation, is a serious concern of this century. Nanoscience and nanotechnology play an important role in addressing a wide range of environmental issues with innovative and successful solutions. Identification and control of emerging chemical contaminants have received substantial interest in recent years. As a result, there is a need for reliable and rapid analytical tools capable of performing sample analysis with high sensitivity, broad selectivity, desired stability, and minimal sample handling for the detection, degradation, and removal of hazardous contaminants. In this review, various gold–carbon nanocomposites-based sensors/biosensors that have been developed thus far are explored. The electrochemical platforms, synthesis, diverse applications, and effective monitoring of environmental pollutants are investigated comparatively.

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