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pISSN : 1976-4251 / eISSN : 2233-4998

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2020, Vol.30, No.2

  • 1.

    Preparation and characterization of black liquor-derived activated carbon by self-chemical activation

    Kim Yong-Jung | Hong Ikpyo | Joongpyo Shim and 1other persons | 2020, 30(2) | pp.115~121 | number of Cited : 0
    Abstract
    A highly functional, environmentally friendly carbonaceous adsorbent material using black liquor (a by-product from the pulp manufacturing) was produced and characterized. This study showed the efect of self-chemical activation driven by inherent alkali, originated from the unique composition of black liquor. A preparation of the micropore-dominant activated carbon was made in an easy and simple manner. The specifc surface areas of samples were found to be 718–1591 m2 /g variated upon heat treatment conditions. The sample activated at 850 °C (50 min as retention time) showed the maximum specifc surface area of 1591 m2 /g with 13.6% as a production yield. Considering the factors infuencing pore structure of activated carbon materials in this study, it was confrmed that mesopore-related surface area increased gradually as the activation temperature and retention time increased. It is noteworthy to address that economically valuable micropore-dominant activated carbon can be produced by a simple heat treatment of the waste material, black liquor. The activated carbon sample derived from black liquor can be applied to various felds, such as environment and energy storage.
  • 2.

    High-efficiency adsorption for both cationic and anionic dyes using graphene nanoribbons formed by atomic-hydrogen induced single-walled carbon nanotube carpets

    Gao Yan | Liang Xilong | Han Shuangping and 7other persons | 2020, 30(2) | pp.123~132 | number of Cited : 0
    Abstract
    Carbonaceous materials are considered as potential adsorbents for organic dyes due to their unique structures which provide high aspect ratios, hydrophobic property, large efcient surface area, and easy surface modifcation. In this work, graphene nanoribbons (GNRs) were prepared by atomic hydrogen-induced treatment of single-walled carbon nanotube (SWCNTs), which inspire the idea of cutting and unzipping the SWCNTs carpets with the modifed in molecules prevent because of the unfolding of the side-walls. The unfolded spaces and uniform vertical arrangement not only enhance the active surface area, but also promote the electrostatic and π–π interactions between dyes and GNRs. The improved adsorption capacity of GNRs beyond original SWCNTs can be determined by the adsorption kinetics and isotherm, which are evaluated through adsorption batch experiments of the typical cationic methylene blue (MB) and anionic orange II (OII) dye, respectively. It is shown that the adsorption kinetics follow a pseudo second-order model while the adsorption isotherm could be determined by Langmuir model. The results reveal that the maximum adsorption capacities of GNRs for MB and OII are 280 and 265 mg/g, respectively. The GNRs present the highly efcient, cost efective, and environmental friendly properties for the commercial applications of wastewater treatment.
  • 3.

    Self-nitrogen-doped carbon materials derived from the petioles and blades of apricot leaves as metal-free catalysts for selective oxidation of aromatic alkanes

    Sun Yongbin | Hao Junlei | Zhu Xuesai and 5other persons | 2020, 30(2) | pp.133~141 | number of Cited : 0
    Abstract
    Carbon materials with tailorable structures and superior properties have great potential applications in environmental protec�tion, energy conversion, and catalysis. Plant biomass as abundant and green non-toxic raw materials has been considered as good precursors for synthesizing heteroatom-doped carbon materials. However, few studies have been reported on the dif�ferent natures of carbon materials derived from diferent parts of the same plant biomass. In this study, we prepared carbon materials from the petioles and blades of apricot leaves by direct pyrolysis without additives. Detailed characterizations indicate that these two carbon materials are similar in element composition and graphitization degree, but difer greatly in surface area and pore volume. These diferences can be attributed to the diferent contents of inorganic salts, vascular bundles, and proteins in petioles and blades. When used as catalysts for the oxidation of ethylbenzene, the petiole-derived carbon shows better catalytic performance than the blades derived carbon due to its high surface area, large average pore size, and doped nitrogen atoms. Furthermore, the carbon catalysts derived from the petioles and blades of poplar leaves and parasol tree leaves show the same diference in catalytic reaction, implying that the above-mentioned conclusion is rather universal, which can provide reference for the synthesis of carbon materials from leaves.
  • 4.

    Characterization of short-length multi-walled carbon nanotubes and cytotoxicity on MDA-MB-231 and HUVEC cell lines

    Dinç Bircan | Ünlü Ayhan | Bektaş Muhammet | 2020, 30(2) | pp.143~153 | number of Cited : 0
    Abstract
    Multi-walled carbon nanotubes (MWNTs) are suitable for delivering large biomolecules with lower cytotoxicity values and low prime cost. Surface modifcations of MWNTs afect interaction with cells and proteins. Oxidation with strong acids decreases cytotoxicity of CNTs and increases protein-loading capacity. Here, after oxidation, TEM images revealed more aligned structure and carboxylated groups at the surface which decreases toxicity. Functionalized MWNTs showed more gradual degradation than the pristine MWNTs and mass loss increased by 2% in the same temperature range. Raman spectroscopy corrected graphitic structure with characteristic D and G bands at 1330 and 1579 cm−1 and increased intensity after oxidation. FTIR spectroscopy peaks at 1443 cm−1, 1560, 1640 cm−1, 2100–2200 cm−1 and 3426 cm−1 are ascribed to C–O–C vibrational stretch, C=C bonds, vibration of C≡C bonds and stretch of hydroxyl groups, respectively. The sonication�driven dispersion of in phosphate-bufered saline, distilled water and cell culture medium were detected by UV–vis–NIR spectroscopy, water-dispersed functionalized MWNTs revealed the highest absorbance value. Cytotoxicity of MWNTs was investigated before and after functionalization in breast cancer (MDA-MB-231) and human vein endothelial (HUVEC) cells. Relatively low-toxicity results were obtained in functionalized MWNTs and cellular uptake of MWNTs were corrected with fuorescent imaging of cells and cell lysates. Protein-loading capacity of fsMWNTs (functionalized short-length multi-walled carbon nanotubes) was evaluated by using bovine serum albumin (BSA) and with an equal amount of fsMWNTs and BSA; 36% binding yield was obtained. Protein corona after covalent functionalization potentially lowered cytotoxicity up to 6%
  • 5.

    Development of microporous-activated carbons derived from two renewable precursors for CO2 capture

    Gomez-Delgado E. | Nunell G. V. | Cukierman A. L. and 1other persons | 2020, 30(2) | pp.155~164 | number of Cited : 0
    Abstract
    Wood sawdust from an invasive arboreal species, Parkinsonia aculeata, and seeds from a tropical fruit of massive consump�tion, Pouteria sapota, were used as precursors for the development of activated carbons (ACs) directed to CO2 adsorption. Chemical activation employing KOH as activating agent and pre-established experimental conditions was applied. Main physicochemical properties of the ACs in relation to their CO2 adsorption performance were examined. The ACs developed from the wood sawdust and the seeds presented specifc surfaces areas of 770 and 1000 m2 g−1, respectively, with their porosity development resulting essentially microporous (< 2 nm). They also showed a similar content of acidic surface groups, but basic functionalities of the former duplicated those of the latter. Maximum CO2 adsorbed at equilibrium (273 K and 100 kPa) was 5.0 mmol g−1 and 4.4 mmol g−1 for the samples derived from the sawdust and the seeds, respectively. On the other hand, CO2 adsorption capacities mimicking post-combustion conditions, as evaluated from thermogravimetric assays and breakthrough curves obtained in a packed-bed column, were approximately 1 mmol g−1, indicating a good CO2 adsorption performance for both ACs. Nevertheless, those derived from the wood sawdust with a notorious preeminence of micropores (~ 93%), narrower pore size distribution centered around 1 nm, and a higher content of basic functionalities than the ACs obtained from the seeds showed a relatively better performance. The CO2 removal capacity of the activated carbons was not noticeably afecte
  • 6.

    Synergetic effect of cross-linking and interfacial interaction in carbon fiber reinforced thermoplastic to enhance its tensile strength by electron-beam irradiation

    Jung Soonyoung | Se Kye Park | GHIM, HAN DO and 2other persons | 2020, 30(2) | pp.165~175 | number of Cited : 0
    Abstract
    A carbon fber reinforced thermoplastic (CFRTP) was irradiated with a high energy electron-beam. As a result, the ten�sile strength of high-density polyethylene (HDPE)-based CFRTPs was signifcantly improved by gradually increasing the electron-beam dose. It was confrmed that the adhesion between CF and HDPE was improved and the surface properties of CF and HDPE were readily modifed by electron-beam. It was verifed from spectroscopic analysis that various oxygen�containing functional groups were formed on the surface of CF and HDPE by irradiation and we believe that strong attrac�tive interactions took place among these functional groups at the interface of CFs and HDPE. Finally, it was conclusive that electron-beam irradiation provided two main efects on CFRTPs. One was cross-linking of thermoplastic resin for efcient load transfer from resin to CF and the other was formation of surface functional group and attractive interaction of these functional groups at the interface of fber and matrix. These two efects showed synergetic contribution to enhance the mechanical properties of CFRTP.
  • 7.

    Small gas adsorption on Co–N4 porphyrin-like CNT for sensor exploitation: a first-principles study

    Zhang Xuanning | Wang Yongjie | Wang Zhenhua and 1other persons | 2020, 30(2) | pp.177~187 | number of Cited : 0
    Abstract
    Using frst-principles theory, we investigated the adsorption performance of CoN4-CNT towards six small gases including NO, O2, H2, H2S, NH3, and CH4, for exploiting its potential application for chemical gas sensors. The frontier molecular orbital theory was conducted to help understand the conductivity change of the proposed material at the presence of gas molecules. The desorption behavior of gas molecules from CoN4-CNT surface at ambient temperature was analyzed as well to determine its suitability for sensing application. Results show that CoN4-CNT is a promising material for O2 and NH3 sensing due to their desirable adsorption and desorption behaviors while not appropriate for sensing NO due to the poor desorption ability and for sensing CH4 and H2 given the poor adsorption behavior. Our calculation would provide a frst insight into the CoN4-embedded efect on the structural and electronic properties of single-walled CNT, and shed light on the application of CoN4-CNT towards sensing of small gases.
  • 8.

    Carbonaceous catalysts from orange pulp for limonene oxidation

    Wróblewska Agnieszka | Serafin Jarosław | Gawarecka Alicja and 5other persons | 2020, 30(2) | pp.189~198 | number of Cited : 0
    Abstract
    The possibility of orange pulp utilization for nanoporous carbons production was investigated. Moreover, processing the obtained materials as limonene oxidation catalysts was studied as well. Limonene was separated from orange pulp obtained from fragmented orange peels—the waste from industrial fruits processing—by means of simple distillation. After the sepa�ration of limonene from the biomass, the dried orange pulp was converted to three types of nanoporous carbon catalysts: without activating agent, with NaOH, and with KOH. The catalysts were characterized by XRD, SEM, EDX, AFM, and sorption of N2 methods. The activities of the obtained catalysts were tested in the oxidation of limonene to perillyl alcohol (the main product), carveol, carvone, and 1,2-epoxylimonene and its diol. In the oxidation processes, hydrogen peroxide was used as the oxidizing agent. This work has shown for the frst time that nanoporous carbons obtained from orange pulp waste, after separation of limonene, are active catalysts for limonene oxidation to industrially important value-added products.
  • 9.

    High porosity activated carbon synthesis using asphaltene particles

    Rabeea Muwafaq Ayesh | Zaidan Tahseen Ali | Ayfan Abdalkareem Hamad and 1other persons | 2020, 30(2) | pp.199~205 | number of Cited : 0
    Abstract
    The study aims to use asphaltene particles (As) extracted from natural bitumen to synthesize activated carbon (ACAs). The asphaltene particles were mixed with a fxed weight of potassium hydroxide (KOH) as an activating agent, preheated to 600 °C, and then treated with 15% hydrofuoric acid (HF). The methylene blue (MB) 20 mg/l was used to determine the adsorption capacity of ACAs and reactivated carbon (RACAs). The morphology of ACAs and its components were character�ized using scanning electron microscopy–energy dispersive X-ray (SEM–EDX) and Fourier-transform infrared spectroscopy (FTIR). The study included the application of adsorption isotherms Freundlich and Langmuir on the experimental data of the studied systems. The yield of ACAs was 92% of the raw material. The activated carbon displayed high adsorption capacity and can be reprocessed after reactivation using microwave radiation. The active surface area of ACAs is found to be 970 m2 /g. The efectiveness and adsorption ability of ACAs and RACAs, as proven by its adsorption capacity (218.15 and 217.907 mg/g) for MB, demonstrate that ACAs and RACAs have a large external surface area and an extensive array of pores. The ACAs are most sensitive at 30 °C and neutral pH. The results also showed that the isotherms have a good ft to the experimented data.
  • 10.

    Preparation of salacca peel-based porous carbons by K2CO3 activation method as cathode materials for LiS battery

    Arie Arenst Andreas | Kristianto Hans | Cengiz Elif Ceylan and 1other persons | 2020, 30(2) | pp.207~213 | number of Cited : 0
    Abstract
    Salacca peel-based porous carbon (SPPC) with high surface area (1945 m2 g−1) and large specifc pore volume (1.68 cm3 g−1) was prepared by pre-carbonization and K2CO3 activation method. Based on the TGA results, it can be estimated that up to 70 wt% of sulfur-active materials could be infltrated into the pores of SPPC to form SPPC/S composite cathode for LiS battery. The porous structure of SPPC could act as a bufer layer against volume expansion and minimize the shuttle efect due to the penetration of intermediate polysulfdes during cycle tests. Optimization on sulfur loading (50, 60 and 70 wt%) in SPPCC/S composite was also investigated. It was found that the SPPC/S composites with 60 wt% of sulfur loading had the best electrochemical performances. With 60 wt% of sulfur loading, SPPC/S composite electrodes showed excellent electrochemical performances in terms of high initial specifc discharge capacity of 1006 mAh g−1 at 0.5 C and capacity retention of 71% until the 100th cycle. For both cases of low and high sulfur loading, they caused much worse electrochemical performances. Based on the experimental results, it can be concluded that porous carbons derived from the salacca peel were promising materials for sulfur loading in LiS battery.
  • 11.

    Catalytic growth of MWCNT using CVD and its application as opto-electronic humidity sensor

    Singh Ekta | Kumar Utkarsh | Srivastava Richa and 1other persons | 2020, 30(2) | pp.215~224 | number of Cited : 0
    Abstract
    The present paper describes the efect of co-catalyst on the growth of multiwall carbon nanotube (MWCNT) by chemical vapor deposition (CVD) technique. The fascinating properties of CNT make them a suitable material for optoelectronic devices such as sensors, LED, solar cell, and feld emission displays. MWCNTs were fabricated using CVD, by decomposing ethanol over fnely dispersed Co metal as a catalyst at 750 °C. The efects of growth condition on the quality and morphology of MWCNTs were investigated by SEM, FTIR and XRD. SEM photographs show that the nanotubes are densely packed having a diameter of 10–15 nm. The bandgap was calculated by UV–visible spectroscopy and it was found varying from 3.08 to 3.5 eV by changing the substrates. The average size of tubes (length) was found to be 250 nm. FTIR exhibited that the synthesized MWCNTs were semiconducting in nature with the oxygen vacancies causing the variations in refractive index with the exposure of moisture.
  • 12.

    Green and economical synthesis of graphene–silver nanocomposite exhibiting excellent photocatalytic efficiency

    Chandu Basavaiah | Kurmarayuni Chandra Mohan | Kurapati Swarnalatha and 1other persons | 2020, 30(2) | pp.225~233 | number of Cited : 1
    Abstract
    The emergence of green methods for the synthesis of graphene-based composites became the gateway for the solution of pollution and economic synthetic methods. Herein, we reported a single step in situ synthesis of reduced graphene oxide sheets decorated with silver nanoparticles (CRG–Ag nanocomposite) using custard apple leaf extract as an efective reduc�ing and stabilizing agent. The ultraviolet–visible, Fourier transform infrared and Raman techniques revealed a primary confrmation about the formation of the said nanocomposite. The X-ray difraction studies confrmed the face-centred cubic crystal structure of silver nanoparticles (Ag NPs) of 30 nm in size. The high-resolution scanning electron microscope spectra revealed the uniform distribution of Ag NPs on the graphene sheets. This simple, novel and rapid approach enabled a facile production of homogeneously deposited Ag NPs on graphene sheets. Thus synthesized CRG–Ag nanocomposite showed excellent photocatalytic efciency of 96% in 2 h under sunlight using methylene blue as a model pollutant.