• Carbon letters
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• v.15 no.4
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• pp.219-237
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• 2014

The element carbon has been used as a source of energy for the past few hundred years, and now in this era of technology, carbon has played a significant and very prominent role in almost all fields of science and technology. So as an honour to this marvellous element, we humans should know about its various forms of existence. In this review article, we shed light on all possible carbon-allotropes; similarities in their synthesis techniques and the starting materials; their wide range of possible availability; and finally, future perspectives and applications. A brief introduction is given on the types, structures, and shapes of the allotropes of carbon for a better understanding.

• Carbon letters
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• v.2 no.1
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• pp.37-43
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• 2001

Mercury has been identified as a potential health and environmental hazardous material. Activated carbon adsorption offers promising potential for the control of mercury emissions, and sulfur impregnated (sulfurized) activated carbons has been shown to be an effective sorbent for the removal of vapor phase $Hg{\circ}$ from sources. In this work, vapor phase mercury adsorption by sulfur impregnated activated carbons were investigated. Sulfur impregnated activated carbons were made by variation of impregnation temperature, and the comparison of adsorption characteristics with commercial virgin and sulfurized carbons were made. Factors affecting the adsorption capacity of virgin and sulfurized activated carbons such as pore characteristics, functional groups and sulfur impregnation conditions were discussed. It was found that the sulfur allotropes plays a critical role in adsorption of mercury vapor by sulfurized activated carbons.

• Applied Microscopy
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• v.48 no.4
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• pp.126-127
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• 2018

Carbon has numerous allotropes and various crystalline forms with full dimensionalities such as diamond, graphite, fullerenes, and carbon nanotubes leading a wide range of applications. Since the emerge of graphene consisting of a single atomic layer of carbon atoms, a fabrication of all-carbon-based device with combination of one-, two-, and three-dimensional carbons has become a hot issue. Here, we introduce an ultimate one-dimensional carbon atomic chain. Carbon atomic chains were experimentally created by removing atoms from monolayer graphene sheet under electron beam inside transmission electron microscope (TEM). A series of TEM images demonstrate the dynamics of carbon atomic chains over time from the formation, transformation, and then breakage.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.780-786
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• 2011

Mg hydride had high hydrogen capacity (7.6%), lightweight and low cost materials and it was promising hydrogen storage material at high temperature. However, commercial applications of the Mg hydride are currently hindered by its high absorption/desorption temperature, and very slow reaction kinetics. one of the approaches to improve the kinetic is $MgH_x$ intermixed with carbon. And it shows that carbon and carbon allotropes have a beneficial effect on hydrogen sorption in Mg. The graphene is a kind of carbon allotropes which is easily desorbed reaction at low temperatures because its reaction is exothermic. In this work, the effect of graphene concentration on the kinetics of Mg hydrogen absorption reaction was investigated. The $MgH_x$-Graphene composites has been prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by XRD and simultaneous TG, DSC analysis. The hydrogenation behaviors were evaluated by using a sievert's type automatic PCT apparatus. In this research, results of kinetic profiles exhibit hydrogen absorption rate of $MgH_x$-5wt.% and 10wt.% graphene composite, as 1.25wt.%/ms, 10.33wt.%/ms against 0.88wt.%/ms for $MgH_x$ alone at 473K.

• Advances in nano research
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• v.5 no.3
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• pp.245-251
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• 2017

Multiwalled carbon-nanotubes (MWCNT) and micro-structured carbon, such as biochar or activated carbon (AC), have been seen to significantly increase the growth indices of certain plant species such as maize (Zea mays L.). Seed imbibition is the stage where environmental factors that affect water transport across the seed coat barrier, make a large impact. This work explores the effect on water imbibition by maize seeds when the aqueous environment surrounding the seed is diluted by small concentrations (10 and 20 mg/l) of pristine MWCNT (p-MWCNT), carboxylate functionalized MWCNT (COO-MWCNT) and AC. The degree of sensitivity of the process to (i) large structural changes is seen by utilizing the nano (the MWCNT) and the micro (the AC) allotropic forms of carbon; (ii) to small changes in the purity and morphology of the p-MWCNT by utilizing 95% pure and 99% pure p-MWCNTs of slightly differing morphologies; and (iii) to MWCNT functionalization by using highly pure (97%) COO-MWCNT. Water imbibition was monitored over a 15 hour period by Near Infrared Thermography (NIRT) and also by seed weighing. Seed surface topography was seen by SEM imaging. Analysis of the NIRT images suggests rapid seed surface topological changes with the quantity of water imbibed. While further work is necessary to arrive at a conclusive answer, this work shows that the imbibition phase of the maize seed is sensitive to the presence of MWCNT even to small differences in the purity of the p-MWCNT and to small differences in the physicochemical properties of the medium caused by the hydrophilic COO-MWCNT.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.162-173
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• 2022

The development of new materials is an essential key for unraveling the environmental and energy problems all over the world. Among the various application materials in this area, crystalline and two-dimensional carbon materials have been studied from points of view such as electrical conductivity, chemical stability, and surface engineering due to the assembly of honeycomb and sp/sp² hybridization structure. Novel two-dimensional materials, including graphene and graphyne, have been continuously reported for several decades to develop in renewable energy fields. Also, various pristine/engineered two-dimensional carbon allotropes have been researched to combine metal nanoparticles in the form of a sphere, cubic, and so on. The renewable energy performance to apply for these materials is drastically increased. In this review, we introduce the research points of the 2D carbon allotrope materials, graphene and graphyne, and applications to improve the performance of renewable energy applications.

• Carbon letters
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• v.26
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• pp.81-87
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• 2018

Morphological differences in multi-layered graphene flakes or graphene nanoplatelets prepared by oxidative (rGO-NP, reduced graphene oxide-nanoplatelets) and non-oxidative (GIC-NP, graphite intercalation compound-nanoplatelets) routes were investigated with various analytical methods. Both types of NPs have similar specific surface areas but very different structural differences. Therefore, this study proposes an effective and simple method to identify structural differences in graphene-like allotropes. The adsorptive potential peaks of rGO-NP attained by the density functional theory method were found to be more scattered over the basal and non-basal regions than those of GIC-NP. Raman spectra and high resolution TEM images showed more distinctive crystallographic defects in the rGO-NP than in the GIC-NP. Because the R-ratio values of the edge and basal plane of the sample were maintained and relatively similar in the rGO-NP (0.944 for edge & 1.026 for basal), the discrepancy between those values in the GIC-NP were found to be much greater (0.918 for edge & 0.164 for basal). The electrical conductivity results showed a remarkable gap between the rGO-NP and GIC-NP attributed to their inherent morphological and crystallographic properties.

• Membrane Journal
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• v.31 no.2
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• pp.101-119
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• 2021

The demand for clean water is virtually present in all modern human societies even as our society has developed increasingly more advanced and sophisticated technologies to improve human life. However, as global climate change begins to show more dramatic effects in many regions in the world, the demand for a cheap, effective way to treat wastewater or to remove harmful bacteria, microbes, viruses, and other solvents detrimental to human health has continued to remain present and remains as important as ever. Well-established synthetic membranes composed of polyaniline (PANI), polyvinylidene fluoride (PVDF), and others have been extensively studied to gather information regarding the characteristics and performance of the membrane, but recent studies have shown that making these synthetic membranes conductive to electrical current by doping the membrane with another material or incorporating conductive materials onto the surface of the membrane, such as allotropes of carbon, have shown to increase the performance of these membranes by allowing the adjustability of pore size, improving antifouling and making the antibacterial property better. In this review, modern electrically conductive membranes are compared to conventional membranes and their performance improvements under electric fields are discussed, as well as their potential in water filtration and wastewater treatment applications.