Activated Carbon Nanocomposite Research Articles

Magnetic activated carbon nanocomposite from Nigella sativa L. waste (MNSA) for the removal of Coomassie brilliant blue dye from aqueous solution: Statistical design of experiments for optimization of the adsorption conditions

The present work was carried out to evaluate the removal of Coomassie brilliant blue dye by adsorption onto a magnetized activated carbon nanocomposite (MNSA) prepared from Nigella sativa L. (NS) waste. Different techniques, including infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption, were used to characterize MNSA to investigate its adsorption properties. Adsorption experiments were carried out by simultaneously optimizing four variables that usually present a strong effect in adsorption studies. A full 24 factorial design with 3 central points was used. The four independent variables were the initial pH of the dye solution (pH), the initial dye concentration (Co), the adsorbent mass (m), and the contact time (t). The sorption capacity (q) of the adsorbent and the percentage of dye removal (% Rem) from an aqueous solution were used as the responses of the factorial design. The results indicated that pH, Co, and m were essential factors for the overall optimization of both responses (q and % Rem) and that several interactions of two, three and four factors occurred. Based on the design of the experiments (DOE), the optimized conditions for adsorption were pH = 2.00, Co = 40.0 mg L-1, m = 30.0 mg, and t = 3.0 h. Under these conditions, both responses, q and % Rem, were maximized, with a desirability of 85.54%. The findings of this study could be useful for industrial wastewater treatment systems.

Optimization of Chitosan+Activated Carbon Nanocomposite. DFT Study

First, the minimum energy (geometry optimization DFT-DMol3) is obtained among C48 optimized ring carbon-system, and one non-optimized chitosan copolymer unit. Second, C24 and C9 optimized rings, each one interacting with an optimized chitosan copolymer unit (Ch). With the aim to investigate structural properties, the first case is optimized by applying smearing; and the second without smearing. Two parallel hypothetical carbon chains of 12 carbon atoms, symmetrically arranged are optimized in C24 carbyne ring; and one hypothetical 5 carbon-chain parallel to another 4 carbon-chain end optimized in a cumulene C9-ring. These carbon-ring structures here defined as activated carbons (AC), correspond to big pore size diameter obtained without chemical agent acting on them. Single point calculations are to build potential energy surfaces with GGA-PW91 functional to deal with exchange correlation energies for unrestricted spin, all-electron with dnd basis set. Only in the first case, orbital occupation is optimized with diverse smearing values.

Synthesis of EDTA-modified magnetic activated carbon nanocomposite for removal of permanganate from aqueous solutions

Abstract In this study, activated carbon particles were magnetized by different amounts of maghemite in different temperatures using co-precipitation method and the resultant nanocomposite were modified with ethylenediaminetetraacetic acid (EDTA) to increase the permanganate contaminants adsorption capacity and to prevent degradation and oxidation of maghemite nanoparticles. Various properties of nanocomposite were investigated using different techniques including, vibrating sample magnetometer, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectrometer. Different kinetics, isotherms and thermodynamic models of adsorption process were investigated. Comparing data with kinetic models showed that the adsorption process complies with the pseudo-second-order kinetic model. The study of equilibrium isotherms data at different temperatures indicated that the adsorption process is more compatible with Langmuir model. Negative values of ΔG and positive values of ΔH revealed that adsorption process is spontaneous and endothermic. Response surface methodology was used to determine optimal parameters of an adsorbent dose of 1 g L−1, pH = 2 and initial permanganate concentration of 50 mg L−1, according to which, the maximum capacity of permanganate adsorption obtained under optimal conditions was 93.86 mg g−1.

Magnetic activated carbon as a sustainable solution for removal of micropollutants from water

A new hydrothermal method was developed to prepare magnetic activated carbon nanocomposite to remove six micropollutants (Triclosan, Bisphenol-A, Tonalide, Metolachlor, Ketoprofen and Estriol) from water. These emerging pollutants are mainly coming from anthropogenic sources. Results indicated that the synthesized magnetic activated carbon was successfully used as a separable adsorbent for removing the micropollutants from water. Adsorption results were modeled by Langmuir and Freundlich isotherms, which showed a better fit of data to the Langmuir model. The adsorbent showed good adsorption performance in which Bisphenol-A and Tonalide were the most effectively removed compounds, with 96 and 93% removal using 0.35 mg of the adsorbent within 40 min in a 50-mL sealed glass vial, respectively. Sedimentation studies were performed to compare the settleability of the adsorbent with powdered activated carbon revealing the superiority of the adsorbent. Thermodynamics of the adsorption of the micropollutants onto the magnetic activated carbon showed the adsorption process was endothermic and spontaneous. Adsorbent regeneration studies were performed with methanol, ethanol, HCl, NaOH and H2O2 in five regeneration cycles. Methanol treatment ensured the highest level of restoration. Overall, the adsorbent can be used as a sustainable treatment to remove studied micropollutants from aqueous solutions.

Optical and photocatalytic properties of the Fe-doped TiO2 nanoparticles loaded on the activated carbon

In this work, Fe-doped (1 wt%) TiO2 loaded on the activated carbon nano-composite was prepared using a sol-gel method. A prepared nano-composite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), BET surface area, Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) spectroscopy and UV–Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the nano-composite was evaluated through degradation of synthetic textile wastewater, reactive red 198, under visible light irradiations. The XRD result indicated that the TiO2 nano-composite contained only anatase phase. The surface area of the TiO2 increased from 48 m2/g to 100 m2/g through the fabrication of the nano-composite. The FE-SEM results indicate that the TiO2 particles with an average particle size of 35–70 nm can be deposited homogeneously on the activated carbon surface. DRS showed that the Fe doping in the TiO2 -activated carbon nano-composite induced a significant red shift of the absorption edge and then the band gap energy decreased from 3.3 to 2.9 eV. Photocatalytic results indicated that the photocatalytic activity of the Fe doped TiO2 increased under visible light irradiation in the presence of the activated carbon.

$$\mathrm{NiFe}_{2}\mathrm{O}_{4 }$$ NiFe 2 O 4 nanoparticles-decorated activated carbon nanocomposite based electrochemical sensor for selective detection of dopamine in presence of uric acid and ascorbic acid

We propose an electrochemical sensor using $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ nanoparticles-decorated activated carbon (AC) nanocomposite for selective detection of dopamine (DA) in the presence of uric acid (UA) and ascorbic acid (AA). The nanocomposite was prepared by a simple hydrothermal method and the characterization was done using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectroscopy. The $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ -AC-modified glassy carbon electrode (GCE) showed excellent electrocatalytic activity towards DA compared to $$\hbox {NiFe}_{2}\hbox {O}_{4}$$ /GCE and AC/GCE. This is attributed to the synergistic action and the large surface area of the nanocomposite. Differential pulse voltammetry (DPV) was employed for the detection of DA wherein the detection limit of $$0.4\,\upmu \hbox {M}$$ along with a linear range of $$5\,\upmu \hbox {M}$$ to $$100\,\upmu \hbox {M}$$ was deduced. The selective detection of DA in presence of AA and UA was demonstrated. The advantages of the present sensor include the ease of preparation of the nanocomposite, low detection limit, remarkable selectivity, good reproducibility and stability. $$\hbox {NiFe}_{2}\hbox {O}{4}$$ -AC nanocomposite was prepared by a simple hydrothermal method. The nanocomposite exhibited enhanced activity towards electro-oxidation of dopamine and excellent selectivity in the presence of uric acid (UA) and ascorbic acid (AA).

Synthesis of magnetic Fe 3 O 4 /activated carbon nanocomposites with high surface area as recoverable adsorbents

Abstract The magnetic Fe3O4/activated carbon nanocomposites with high surface area were synthetized as recoverable adsorbents by chemical binding of Fe3O4 nanoparticles on activated carbon (AC) powders. The component AC and Fe3O4 in this nanocomposite possesses amorphous non-graphitic structure and cubic crystal structure, respectively. All composite samples presented superparamagnetic properties. The saturation magnetization of Fe3O4/AC nanocomposites was significantly lower than that of bare Fe3O4 particles, indicating that Fe3O4 particles were truly attached on AC surface. The microstructure image indicated that the Fe3O4 particles were uniformly dispersed on AC surface and thus maintained high specific surface area. The adsorption capacity of methyl orange (MO) at 30 °C slightly decreased from 384 mg/g on AC powders to 324 mg/g on Fe3O4/AC nanocomposites, which was reduced by 15% after magnetic fabrication. It was found that MO adsorption on Fe3O4/AC nanocomposites followed the pseudo-second order kinetic model and the isotherms could be described by the Langmuir model. The easy recovery of magnetic adsorbents from aqueous solution demonstrated their application potential to remove toxic pollutants in water and wastewater treatment.

Preparation and Characterization of Polysulfone/Nanosilver-Doped Activated Carbon Nanocomposite

In this study, nano silver-doped activated carbon (Ag/C) acted as an inorganic additive and was blended with a polysulfone (PSF) matrix in a tetrahydrofuran (THF) solution, thereby forming nano silver- doped activated carbon/polysulfone (Ag/C/PSF) composites. Subsequently, the silver content and characterization of the Ag/C were identified using energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The FTIR, XRD, EDS and SEM were used to characterize the structure and morphology of the Ag/C/PSF composites. The FTIR spectra analysis revealed that adding a small volume of Ag/C in a PSF matrix did not substantially affect the functional groups of the matrix. The XRD results showed that the characteristic crystallization peaks of Ag/C/PSF (2θ = 26°) increased as the Ag/C content increased. The EDS results revealed that silver elements were inlaid into Ag/C/PSF composites, and the SEM results demonstrated strong interfacial interaction between the Ag/C particles and PSF matrix. The results of thermogravimetric analysis and differential scanning calorimetry appeared that adding Ag/C particles increased the thermal decomposition temperature and glass transition temperature of the Ag/C/PSF composites. From a stress–strain analysis, the added Ag/C particles enhanced the tensile strength of the PSF matrix. The results of contact-angle and atomic-force microscopy measuring showed that the hydrophobicity and surface roughness increased when Ag/C content increased. The antibacterial test results revealed that the Ag/C/PSF composites exhibited excellent antibacterial activity against both Staphylococcus aureus and Escherichia coli. In addition, the electrical conductivity measurements showed that volume resistivity of the Ag/C/PSF composites decreased with the amount of Ag/C increase.

Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO 2 /sewage sludge-based activated carbon nanocomposites

Nanocomposite TiO2/ASS (TiO2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO2/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO2/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO2 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd2+ from bi-pollutant solution was achieved with TiO2/ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO2/ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO2/ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO2/ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd2+ it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.

Mechanosynthesis and characterization AFe2O4 (A: Ni, Cu, Zn)-activated carbon nanocomposite as an effective adsorbent for removal dodecanethiol

Abstract In this study, nanocomposites of monoferrite-activated carbon (Ferrite-AC) have been prepared by mechanosynthesis technique. Nanocomposites can be utilized as adsorbent for desulfurization of hydrocarbon liquid fuels. Nanocomposites were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDS) analysis, Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmet-Teller (BET) and vibration sample magnetometer (VSM). Results showed that NiFe 2 O 4 -AC had better performance between other adsorbents. Adsorption rate of dodecanethiol was improved by increasing NiFe 2 O 4 -AC concentration. XPS results showed that the dodecanethiol was oxidized by the catalyst surface. BET surface erea of NiFe 2 O 4 -AC nanocomposite was 626 m 2 /g with porous structure.

Fabrication of N-doped &SnO2-incorporated activated carbon to enhance desalination and bio-decontamination performance for capacitive deionization

Abstract Herein, nitrogen-doped tin oxide intercalated activated carbon nanocomposite (N-AC/SnO 2 ) were prepared using hydrothermal strategy and explored as an electrode for capacitive desalination and disinfection. Although tin oxide (SnO 2 ) has good characteristics, the nitrogen must be carefully considered for modifying the characteristics of the carbonaceous materials to improve the performance as an electrode in the CDI process. The characterization of the proposed materials which investigated by XRD, TEM, FE-SEM, XPS and FT-IR affirmed the formation of the nanocomposite. The electrosorption behavior investigated by electrochemical techniques demonstrates that, compared to the specific capacitance of the AC and AC/SnO 2 (207.46 F g −1 and 233.21 F g −1 ), that of the N-AC/SnO 2 is higher at 408.8 F g −1 , and N-AC/SnO 2 exhibits better electrical conductivity. The CDI performance evaluated by batch mode experiments through an applied voltage of 1.2 V in a 50 mg L −1 NaCl aqueous solution shows that the N-AC/SnO 2 electrode introduces a higher electrosorptive capacity of 3.42 mg g −1 , an enhanced desalination efficiency of 61.13%, and good antibacterial performance. Overall, the present study demonstrates that N-AC/SnO 2 has considerable potential as an electrode material for CDI application.

Fuzzy logic modeling of Pb (II) sorption onto mesoporous NiO/ZnCl2-Rosa Canina-L seeds activated carbon nanocomposite prepared by ultrasound-assisted co-precipitation technique

In this study, NiO/Rosa Canina-L seeds activated carbon nanocomposite (NiO/ACNC) was prepared by adding dropwise NaOH solution (2mol/L) to raise the suspension pH to around 9 at room temperature under ultrasonic irradiation (200W) as an efficient method and characterized by FE-SEM, FTIR and N2 adsorption-desorption isotherm. The effect of different parameters such as contact time (0-120min), initial metal ion concentration (25-200mg/L), temperature (298, 318 and 333K), amount of adsorbent (0.002-0.007g) and the solution's initial pH (1-7) on the adsorption of Pb (II) was investigated in batch-scale experiments. The equilibrium data were well fitted by Langmuir model type 1 (R2>0.99). The maximum monolayer adsorption capacity (qm) of NiO/ACNC was 1428.57mg/L. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) were also calculated. The results showed that the adsorption of Pb (II) onto NiO/ACNC was feasible, spontaneous and exothermic under studied conditions. In addition, a fuzzy-logic-based model including multiple inputs and one output was developed to predict the removal efficiency of Pb (II) from aqueous solution. Four input variables including pH, contact time (min), dosage (g) and initial concentration of Pb (II) were fuzzified using an artificial intelligence-based approach. The fuzzy subsets consisted of triangular membership functions with eight levels and a total of 26 rules in the IF-THEN approach which was implemented on a Mamdani-type of fuzzy inference system. Fuzzy data exhibited small deviation with satisfactory coefficient of determination (R2>0.98) that clearly proved very good performance of fuzzy-logic-based model in prediction of removal efficiency of Pb (II). It was confirmed that NiO/ACNC had a great potential as a novel adsorbent to remove Pb (II) from aqueous solution.

Photocatalytic degradation of orange G dye using ZnO/biomass activated carbon nanocomposite

Abstract In the present study zinc oxide/waste biomass activated carbon nano composite (ZnO/WBAC) materials were prepared by hydrothermal methods to obtain controlled particle size with uniform distribution zinc oxide onto activated carbon matrix with different loadings of carbon. Activated carbon used in this study was prepared from waste biomass using physical activation method. The prepared ZnO/WBAC nanocomposite was characterized using FT-IR, XRD, UV-DRS, HRSEM and EDAX. From the UV–vis-DRS data, band gap energies of the synthesized materials were found to be 3.17 eV, 3.04 eV and 2.84 eV for the 3:1, 2:2 and 1:3 ZnO/WBAC nanocomposites respectively. HRSEM analysis showed the spherical ZnO particles formed on the activated carbon material. The particle size was ranged from 25 to 30 nm. The photocatalytic activities of the prepared composite material were evaluated for the degradation of orange G dye under UV and Visible light irradiations. Preliminary studies showed that the catalyst exhibited good activities under neutral pH conditions with an optimum dosage of 1 g/L. The kinetics of photodegradation were carried out at different initial dye concentrations and reactions followed pseudo-first order kinetics. The presence of commonly occurring electrolytes marginally decreased the photoactivity of the catalyst. Reusability studies showed the catalyst to retain its original efficiency even after the third cycle of its reuse.

Magnetically Recoverable and Reusable Antimicrobial Nanocomposite Based on Activated Carbon, Magnetite Nanoparticles, and Silver Nanoparticles for Water Disinfection

Recent advancements in nanotechnology have led to the development of innovative, low-cost and highly efficient water disinfection technologies that may replace or enhance the conventional methods. In this study, we introduce a novel procedure for preparing a bifunctional activated carbon nanocomposite in which nanoscale-sized magnetic magnetite and antimicrobial silver nanoparticles are incorporated (MACAg). The antimicrobial efficacy of the nanocomposite was tested against Escherichia coli (E. coli). MACAg (0.5 g, 0.04% Ag) was found to remove and kill 106–107 CFU (colony-forming units) in 30 min via a shaking test and the removing and killing rate of the nanocomposites increased with increasing silver content and decreased with increasing CFU. The inhibition zone tests revealed, among the relevant components, only Ag nanoparticles and Ag+ ions showed antimicrobial activities. The MACAg was easily recoverable from treated water due to its magnetic properties and was able to remove and kill 106 CFU after multiple-repeated use. The MACAg nanocomposite also demonstrated its feasibility and applicability for treating a surface water containing 105 CFU. Combining low cost due to easy synthesis, recoverability, and reusability with high antimicrobial efficiency, MACAg may provide a promising water disinfection technology that will find wide applications.

Polyethylene-Modified Activated Carbon Nanocomposite for Removal of Methylene Blue from Aqueous Solutions: Characteristic, Kinetic and Thermodynamic Studies

Polyethylene-Modified Activated Carbon Nanocomposite for Removal of Methylene Blue from Aqueous Solutions: Characteristic, Kinetic and Thermodynamic Studies

Novel titanium dioxide–graphene–activated carbon ternary nanocomposites with enhanced photocatalytic performance in rhodamine B and tetracycline hydrochloride degradation

A novel ternary nanocomposite consisting of activated carbon (AC) and titanium dioxide (TiO2) decoration in the presence of reduced graphene oxide (TiO2–rGO–AC) was fabricated by a facile hydrothermal synthesis method for use as a high-performance photocatalyst. The as-prepared TiO2–rGO–AC nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and UV–Vis diffuse reflectance spectroscopy. The results demonstrated that the TiO2 and activated carbon were well dispersed on the rGO surface. The photocatalytic performance of the TiO2–rGO–AC nanocomposite was evaluated as a catalyst for the photodegradation of rhodamine B. The degradation rate was 3.4 times higher than that of pure TiO2 under simulated solar light irradiation. The enhancement of photocatalytic performance is attributed to the adsorption of AC which significantly increased the organic molecule concentration near the catalytic surface, allowing the effective transfer and separation of photogenerated electrons. TiO2–rGO–AC photocatalyst is also effective for the degradation of tetracycline in aqueous solution, suggesting wide application of these nanocomposite materials in various fields including air purification and wastewater treatment.

Preparing and Testing a Magnetic Antimicrobial Silver Nanocomposite for Water Disinfection To Gain Experience at the Nanochemistry–Microbiology Interface

We describe a 2 h introductory laboratory procedure that prepares a novel magnetic antimicrobial activated carbon nanocomposite in which nanoscale sized magnetite and silver particles are incorporated (MACAg). The MACAg nanocomposite has achieved the synergistic properties derived from its components and demonstrated its applicability as an effective and recoverable antimicrobial agent for water disinfection. The principle is successfully illustrated by a significant reduction in the number of microbes in an Escherichia coli (E. coli) solution of 2 × 106 colony forming units following its treatment with MACAg for 10 min. The exercise allows the college students to (1) be introduced to an exciting class of advanced materials, known as nanocomposites, at an early stage, (2) gain working experiences at nanochemistry–microbiology interface, and (3) see the use and experience the fun of chemistry. The experiment uses readily available materials, can be run in a general or introductory chemistry laboratory envi...

Ear-like poly (acrylic acid)-activated carbon nanocomposite: A highly efficient adsorbent for removal of Cd(II) from aqueous solutions

Poly (acrylic acid) modified activated carbon nanocomposite (PAA-AC) was synthesized. The structure and morphology of this nanocomposite were characterized by FTIR, SEM, TEM, XRD and Zeta potential. The adsorption of some heavy metal ions on PAA-AC was studied. The characterization results indicated that PAA-AC was a novel and ear-like nanosheet material with the thickness of about 40nm and the diameter of about 300nm. The adsorption results exhibited that the introduction of carboxyl groups into activated carbon evidently increased the uptake for heavy metal ions and the nanocomposite had maximum uptake for Cd(II). Various variables affecting adsorption of PAA-AC for Cd(II) were systematically explored. The maximum capacity and equilibrium time for adsorption of Cd(II) by PAA-AC were 473.2mgg-1 and 15min. Moreover, the removal of Cd(II) for real electroplating wastewater by PAA-AC could reach 98.5%. These meant that the removal of Cd(II) by PAA-AC was highly efficient and fast. The sorption kinetics and isotherm fitted well with the pseudo-second-order model and Langmuir model, respectively. The adsorption mainly was a chemical process by chelation. Thermodynamic studies revealed that the adsorption was a spontaneous and endothermic process. The results revealed that PAA-AC could be considered as a potential candidate for Cd(II) removal.

Lithium Titanate Confined in Carbon Nanopores for Asymmetric Supercapacitors

As one of the superior anode materials for high power Li-ion batteries and asymmetric supercapacitors, spinel Li4Ti5O12 (LTO), has attracted significant attention in recent years owing to its unique characteristics.[1] Li4Ti5O12 exhibits a flat lithiation potential plateau at the voltage of ~1.55 V vs. Li/Li+, which largely prevents both excessive solid electrolyte interphase (SEI) formation and lithium dendrite growth. In addition, LTO is known for its “near-zero” volume change during repeatable lithiation and delithiation, which contributes to its excellent cyclic stability. One major drawback of LTO to be qualified for high-rate performance is its poor electrical conductivity. One approach to improving electrical conductivity is doping of metal or nonmetal ions in Li, Ti or O sites, though the cyclic stability may be impaired and the resulting rate performance may still be insufficient for practical applications. Another drawback is that the Li-ion transport in LTO is slow compared with that of supercapacitor electrode materials.[2] Therefore, recent endeavors have been devoted to the design of LTO nanostructures and those with porous LTO morphologies, which demonstrated improved kinetics.[3] The synthesis of LTO nanoparticles has been extensively studied, however, it is still rather difficult to prepare uniform Li4Ti5O12 nanoparticles of small dimensions (e.g., < 5-10 nm) due to the high annealing temperature required during synthesis (700-800 oC), at which LTO crystals aggregate and over-grow due to Ostwald ripening. In this research, we report on a novel facile strategy for the low-cost synthesis of uniform Li4Ti5O12- activated carbon nanocomposites (LTO-AC), where crystalline sub – 4 nm LTO nanoparticles are uniformly distributed in the nanopores of the carbon matrix.[4] In contrast to the nanosized particles of various shapes and sizes, which are difficult (and expensive) to handle and utilize in electrodes, micro-scale LTO-AC has the potential to serve as drop-in replacement for AC in supercapacitor electrode production. AC not only serves as spatial confinement to control the growth of LTO nanocrystals, but also as a conductive material to compensate the poor electrical conductivity of LTO. As a result, Li4Ti5O12 nanoparticles in AC pores demonstrated remarkable performance characteristics, showing more than 100 mA h g-1 at the ultra-high rate of 350C (1C= 175 mA g-1), where charge or discharge takes place in ~6 s. When compared with pure AC, the LTO-AC nanocomposites showed up to 12 times higher gravimetric capacity and 12 times higher volumetric capacity. [1] K. Zaghib, A. Mauger, H. Groult, J. Goodenough, C. Julien, Materials 2013, 6, 1028. [2] N. S. Choi, Z. H. Chen, S. A. Freunberger, X. L. Ji, Y. K. Sun, K. Amine, G. Yushin, L. F. Nazar, J. Cho, P. G. Bruce, Angewandte Chemie-International Edition 2012, 51, 9994. [3] Y. Ren, A. R. Armstrong, F. Jiao, P. G. Bruce, Journal of the American Chemical Society 2010, 132, 996. [4] E. Zhao, C. Qin, H.-R. Jung, G. Berdichevsky, A. Nese, S. Marder, G. Yushin, ACS Nano 2016. Figure 1

Preparation and properties of Ag-coated activated carbon nanocomposites produced from wild chestnut shell by ZnCl2 activation

Abstract In this study, the effect of the silver ions which are bonded activated carbons gathered from the wild chestnut shells with chemical reduction method is examined. Activated carbons were obtained from wastes of wild chestnut shells through methods of chemical activation with ZnCl 2 in N 2 atmosphere and characteristics were determined. Adsorption capacity of activated carbons was demonstrated with BET and iodine number. Experiments were carried out at different carbonisation temperatures (600–800 ° C), impregnation time (8–24 h) and impregnation ratio (0.25–1), which had a significant effect on the pore structure and surface area of the carbon. The aim of the conducted study is to research the physicochemical properties of activated carbons and materials with AgNO 3 . Silver nitrate (AgNO 3 ) was added to activated carbons that were obtained through chemical reduction. Characterisation of wild chestnut shell, activated carbons and silver ion covered activated carbons was carried out through the methods of a Brunauer–Emmett–Teller (BET), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), UV–vis absorption spectra (UV) and X-ray diffraction (XRD). Highest BET surface area of the produced activated carbons was determined as 92,660 m²/g at a temperature of 700 ° C in the 24 h of impregnation time and in the activated carbon obtained from 1 impregnation ratio. As a result, it was presented clearly that how the analysed parameters have affected the activated carbon properties and the optimum conditions for producing activated carbons which can be obtained as the result of the chemical application of chosen raw material with ZnCl 2 in the atmosphere of nitrogen. Because the Ag particles block the pores of AC, the BET surface area, total pore volume and average pore diameter of the AC2/Ag samples decreased as the concentration of the AgNO 3 solution increased.