Catalytic Vapor Deposition Research Articles

Nitrogen inclusion in carbon nanotubes initiated by boron doping and chlorination: Their use as electrocatalysts for oxygen reduction reaction

The use of carbon nanostructures doped with heteroatoms as electrocatalysts for oxygen reduction reaction (ORR) has attracted intense research in recent years because they are highly conductive, have good durability, and are highly electro-active. One of the strategies to modify the characteristics of carbon nanomaterials (CNMs) to render them suitable for certain applications is to dope them with boron (B) and nitrogen (N). The effect of doping CNMs with boron has been a subject of little study, and hence, it is not well understood, as compared to nitrogen doping studies. In this study, nitrogen was unintentionally doped into carbon nanotubes (CNTs) by chlorination and decomposition of triphenylborane in a catalytic vapor deposition (CVD) reactor. N-doping resulted from the use of nitrogen as a carrier gas. Microscopic and spectroscopic techniques revealed that N bonding of carbon nanostructures together with the presence of defects played pivotal roles in determining the extent of ORR performance of produced CNMs. The introduction of N in the carbon matrix during B molecule decomposition resulted in the reduction in the amount of B doped into the matrix, due to competitive incorporation of N which inhibited B introduction. The presence of pyridinic N species was responsible for a 2e−ORR performance.

Carbon Nanotubes Synthesized by CCVD Method using Diatomite and Shungite Minerals

In this work, carbon nanotubes were prepared using catalysts consisting of nickel particles supported on the naturally occurring minerals diatomite and shungite. The carbon source for the chemical catalytic vapour deposition (CCVD) synthesis was a propane-butane gas mixture. The synthesized multiwall carbon nanotubes (MWCNT) were characterized using Raman spectroscopy, transmission and scanning electron microscopy, and the effect of temperature on their structure was investigated. The carbon content was determined by thermogravimetric analysis. In Raman spectra of CNTs the intensity ratio I(G)/I(D) for 650 °C is higher than that for 700 °C and then it begins to increase with increasing temperature. The results show that the diameter of CNTs which were synthesized on the surface of diatomite/shungite samples were in the range of 33–100.3 nm. The development of new methods for creating catalytic systems that allow controlling the structure of carbon particles is an important task leading to the improvement of existing approaches to the synthesis of CNTs with certain functional properties.

Atmospheric Pressure Catalytic Vapor Deposition of Graphene on Liquid In and Cu-In Alloy Substrates

Liquid substrates are great candidates for the growth of high-quality graphene using chemical vapour deposition (CVD) due to their atomically flat and defect free surfaces. A detailed study of graphene growth using atmospheric pressure CVD (APCVD) on liquid indium (In) was conducted. It was found that the effect of the growth parameters on the quality of the graphene produced is highly dependent on the properties of the substrate used. A short residence time of 6.8 sec for the reactive gases led to a high graphene quality, indicating the good catalytic behaviour of In. The role of hydrogen partial pressure was found to be crucial, with monolayer and bilayer graphene films with a low defect density obtained at low PH2 (38.6 mbar), whilst more defective, thicker graphene films with a partial coverage being obtained at high PH2 (74.3 mbar). The graphene deposition was insensitive to growth time as the graphene growth on liquid In was found to self-limit to bilayer. For further investigation, five compositions of Cu-In alloys were made by arc-melting. Graphene was then grown using the optimum conditions for In and the quality of the graphene was found to degrade with increasing Cu wt.%. This work will aid the future optimisation of the growth conditions based upon the substrate’s properties.

Efficient Removal of Cationic and Anionic Dyes from Wastewater Using Carbon Nanotubes from Petrochemical Waste Oil

Dye-contaminated wastewater from the textile industry and petrochemical waste oil (PWO) constitute a very serious threat to the environment. The presence of dyes in water inhibits penetration of sunlight, decreasing the photosynthetic processes of aquatic plants, resulting in the disruption of aquatic ecosystems. Moreover, organic dyes are known to have adverse effects on the human health, which presents a risk to the sources of clean drinking water. On the other hand, petrochemical waste oil is difficult to degrade and contains heavy metals and harmful additives. When dumped on landfills, waste oil may seep through the soil and find its way to bodies of water. Recycling technologies are still underdeveloped, and treatment proves to be expensive. Thus, it is crucial to improve the alternative upcycling technology of petrochemical waste oil. Herein, carbon nanotubes (CNT) were synthesized from PWO by simple catalytic vapor deposition (CVD). These CNTs were then used for systematic study on the removal of cationic and anionic dyes from wastewater. Dye removal by the as-synthesized CNT was Langmuir-type adsorption and followed the pseudo-second-order rate model for both the cationic and anionic dyes. Factors like solid-to-liquid ratio, initial dye concentration, and removal efficiency were investigated. CNT from PWO showed a relatively short adsorption time of less than an hour (t~60 min) for both types of dye and demonstrated very high dye adsorption capacities (qm). Hence, this study opens the possibility of using the PWO-derived CNT for large-scale dye-contaminated wastewater treatment.

Fabrication of chlorine nitrogen co-doped carbon nanomaterials by an injection catalytic vapor deposition method

The synthesis of both covalently bonded chlorine and nitrogen-doped carbon materials (Cl-N-CNMs) has been little studied. In this paper we report on the investigation of the synthesis of Cl-N-CNMs using a feedstock containing a mixture of dichlorobenzene (DCB), acetylene and acetonitrile over a Fe-Co/CaCO3 catalyst using an injection CVD method at 800 °C. By varying the acetonitrile:DCB concentration ratio (66.7:33.3; 33.3:66.7 and 20:80), the morphology and physicochemical properties of the CNMs was varied. The products contained varying amounts of Cl (0.5%–1.2%) and N (0.88%–1.47%) and the total amount of Cl and N increased with the Cl content in the feed, as determined by XPS. A graphitic N environment dominated in feeds containing 33.3 and 66.7 vol.% DCB, whilst pyrrolic N dominated in feeds containing pure acetonitrile and 80 vol.% DCB. The chlorine in the feed promoted the formation of CNMs with various shapes namely horn-shaped, spaghetti-like, and pencil-like shapes, some with open-ends and others with closed-ends as determined by TEM and SEM studies. Although no direct correlation with the amounts of the reactants used and the morphology of the products was established, trends in the product shapes were noted with highly defected products produced from 66.7 vol.% DCB, and feeds containing 33.3 and 80 vol.% had tubes with similar open-ended horn-shaped morphology and less defects.

Atmospheric Pressure Catalytic Vapor Deposition of Graphene on Liquid Sn and Cu-Sn Alloy Substrates.

The chemical vapor deposition (CVD) of graphene on liquid substrates produces high quality graphene films due to the defect-free and atomically flat surfaces of the liquids. Through the detailed study of graphene growth on liquid Sn using atmospheric pressure CVD (APCVD), the quality of graphene has been found to have a close relationship with hydrogen flow rate that reflects on hydrogen partial pressure inside the reactor (PH2) and hydrogen solubility of the growth substrates. The role of PH2 was found to be crucial, with a low defect density monolayer graphene being obtained in low PH2 (90.4 mbar), while partial graphene coverage occurred at high PH2 (137.3 mbar). To further understand the role of substrate’s composition, binary alloy with compositions of 20, 30, 50, 60 and 80 wt.% tin in copper were made by arc-melting. Graphene quality was found to decrease with increasing the content of copper in the Cu–Sn alloys when grown using the conditions optimised for Sn substrates and this was related to the change in hydrogen solubility and the high catalytic activity of Cu compared to Sn. This shall provide a tool to help optimising CVD conditions for graphene growth based on the properties of the used catalytic substrate.

Fine-tuning the catalytic activity by applying nitrogen-doped carbon nanotubes as catalyst supports for the hydrogenation of olefins

Nitrogen-free multi-wall carbon nanotubes (MWCNTs) and N-doped bamboo-like carbon nanotubes (BCNTs) were synthesized by using catalytic vapor deposition (CVD) and used as catalyst support materials. Pd, Rh, Ru, and Ir have been deposited onto the nanotubes to achieve metal/nanotube catalysts. The catalytic activity of the samples was fine-tuned by changing the type of support. BCNT supported Pd and Rh (Pd/BCNT, Rh/MWCNT) catalysts were found to be the most active for liquid phase hydrogenation of octadecene amongst these samples. The initial olefin hydrogenation rate of the Pd/BCNT sample was slightly higher than the corresponding MWCNT-supported catalyst. Based on the hydrogenation reaction, the performance of these catalyst had been ranked as follows: Pd/BCNT ≈ Rh/MWCNT > Pd/MWCNT > Rh/BCNT > > Ir/MWCNT > Ru/BCNT > Ir/BCNT > Ru/MWCNT. The structural properties of chemisorbed Pd on MWCNT and N- BCNT were also characterized by means of computational chemical methods in order to shed some light on the nature of metal binding properties of N-doped and undoped surfaces. The calculations shown preference towards the edges of the surfaces which is in good agreement with the experimental findings.

The low-temperature specific heat of MWCNTs

The specific heat of multi-walled carbon nanotubes (MWCNTs) with a low defectiveness and with a low content of inorganic impurities has been measured in the temperature range from 1.8 to 275 K by the thermal relaxation method. The elemental composition and morphology of the MWCNTs were determined using scanning electron microscopy analysis and energy dispersion x-ray spectroscopy. The MWCNTs were prepared by chemical catalytic vapor deposition and have mean diameters from 7 nm up to 18 nm and lengths in some tens of microns. MWCNTs purity is over 99.4 at.%. The mass of the samples ranged from 2–4 mg. It was found that the temperature dependence of the specific heat of the MWCNTs differs significantly from other carbon materials (graphene, bundles of SWCNTs, graphite, diamond) at low temperatures. The specific heat of MWCNTs systematically decreases with increasing diameter of the tubes at low temperatures. The character of the temperature dependence of the specific heat of the MWCNTs with different diameters demonstrates the manifestation of different dimensions from 1D to 3D, depending on the temperature regions. The crossover temperatures are about 6 and 40 K. In the vicinity of these temperatures, a hysteresis is observed.

Electroconductive textile coatings from pastes based on individualized multi-wall carbon nanotubes – Synergy of surfactant and nanotube aspect ratio

We report on preparation, application and fixation of electrically conductive and flexible coatings of surface resistivity 110 Ω/sq. The most promising coatings were obtained from pastes exploiting synthesized in-house – via chemical catalytic vapour deposition (c-CVD)– 200 μm-long multi-wall carbon nanotubes (MWCNTs). MWCNTs were finely dispersed in water using a surfactant pre-selected according to ‘individualizing’ power measured by centrifugation-stability in UV–vis spectroscopy. The influence of MWCNT aspect ratio on: the resulting dispersion stabilities, and physicochemical compatibilities of nanotubes with aqueous solutions of surfactants was clearly demonstrated by comparative studies of individualized in-house (aspect ratio = 3000) versus commercial Nanocyl NC7000TM (aspect ratio = 150) MWCNTs. The individualized MWCNTs were used as the further conductive components of acrylic resin-based pastes towards flexible and conductive textile coatings. The results fall within the understanding of production of conductive coatings for e-textiles – the field with numerous every-day life applications from medicine, e.g. in electrocardiography, to fashion to military.

Synthesis of graphene by in situ catalytic chemical vapor deposition of reed as a carbon source for VOC adsorption.

Few-layer graphene was synthesized by in situ catalytic carbon vapor deposition (CCVD) method, using reed as a carbon source and Ni, Cu, and Mg salts as the catalyst compounds. The synthesized graphene was also used for adsorption of VOCs. Furthermore, the effect of organic additives, sorbitol, and citric acid on catalyst compounds was investigated by temperature-programmed reduction analysis (H2-TPR). The products' properties were characterized by thermo-gravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) surface area analysis. TEM and FE-SEM images confirmed the formation of graphene sheets. Activation of the graphene by phosphoric acid at 500°C and then by CO2 at 800°C increased the surface area from 298 to 568m2/g. Gasoline working capacity of the activated graphene was 65.24g/ladsorbent. Graphical abstract Few-layer graphene was synthesized by in situ catalytic carbon vapor deposition (CCVD) method using reed as a carbon source and Ni, Cu, and Mg salts as the catalyst compounds and used for adsorption of VOCs.

Heterostructured Nanorings of Fe-Fe3O4@C Hybrid with Enhanced Microwave Absorption Performance.

Microwave absorption is a critical challenge with progression in electronics, where fine structural designing of absorbent materials plays an effective role in optimizing their microwave absorption properties. Here, we have developed Fe3O4@C (FC) and Fe-Fe3O4@C (FFC) hybrid nanorings via a hydrothermal method coupled with a chemical catalytic vapor deposition technique. FC and FFC hybrid nanorings have fine carbon coating while their size can easily be tunable in a certain range from 80-130 to 90-140 nm. The optimized FC and FFC hybrid nanorings bear minimum reflection loss (RL) values of -39.1 dB at 15.9 GHz and -32.9 dB at 17.1 GHz, respectively, whereas FFC shows an effective absorption bandwidth (RL values < -10 dB) ranged from 5.2 to 18 GHz. Such an enhanced microwave absorption performance of hybrid nanorings is mainly due to the suitable impedance characteristics, multilevel interfaces, and polarization features in nanorings. This work provides an approach to design hybrid materials having a complex structure to enhance the microwave absorption properties.

Mechanical performance of HMA-2 modified with purified and unpurified carbon nanotubes and nanofibers

The present study evaluates the mechanical performance of a Hot Mix Asphalt – Type II (HMA-2) modified with carbon nanotubes and carbon nanofibers (CNTF). CNTF were made by means the Catalytic Vapor Deposition (CVD) technique at 700° C using a Nickel, Copper and Aluminum (NiCuAl) catalyst with a Cu/Ni molar relation of 0,33. In order to properly assess HMA-2 performance, three different mixtures were analyzed: 1) HMA-2 modified with purified CNTF; 2) HMA-2 modified with non-purified CNTF and, 3) a Conventional HMA-2 (control). Samples manufactured in accordance with the Marshall Mix Design were tested in the laboratory to study rutting, resilient modulus (Mr) and fatigue. In addition to the aforementioned dynamic characterization, the effect of CNTF purification on the asphalt mixture’s mechanical properties was analyzed. In short, a comparative study was designed to determine whether or not CNTF should be purified before introduction into the HMA-2. This investigation responds to the growing demand for economical materials capable of withstanding traffic loads while simultaneously enhancing pavement durability and mechanical properties. Although purified CNTF increased HMA-2 stiffness and elastic modulus, non-purified CNTF increased the asphalt mixture’s elastic modulus without considerable increases in stiffness. Thus, the latter modification is deemed to help address fatiguerelated issues and improve the long-term durability of flexible pavements.

Hybrids of Iron-Filled Multiwall Carbon Nanotubes and Anticancer Agents as Potential Magnetic Drug Delivery Systems: In Vitro Studies against Human Melanoma, Colon Carcinoma, and Colon Adenocarcinoma

Cell type, morphology, and functioning are key variables in the construction of efficient “drug-vehicle” hybrids in magnetic drug delivery. Iron-encapsulated multiwall carbon nanotubes (Fe@MWCNTs) appear as promising candidates for theranostics due to in situ chemical catalytic vapor deposition (c-CVD) synthesis, straightforward organic functionalization, and nanoneedle (1D) behavior. Here, model hybrids were synthesized by exploring C-sp2 chemistry ((1+2)-cycloaddition of nitrenes and amidation) of the outer MWCNT walls combined with anticancer agents, that is, 5-fluorouracil (5FU), purpurin (Purp), and 1,8-naphthalimide DNA intercalators (NIDIs), via linkers. Analyses of the Fe@MWCNT vehicles by SEM, TEM, and Raman spectroscopy revealed their morphology while Mössbauer spectroscopy confirmed the presence of encapsulated ferromagnetic iron-based nanodomains. Cytotoxicity of the hybrids was studied using a 24 h MTS assay combined with the apoptosis and life cycle assays against human melanoma (Me45), colon carcinoma (HCT116+), and colon adenocarcinoma (Caco-2). The cells had different sensitivity to the vehicles themselves as well as to the hybrids. MWCNT-based covalent hybrids of 5FU and Purp emerged as the most promising systems against Me45 and HCT116+ cell lines with the highest in vitro cytotoxicity and proapoptotic activity. Furthermore, nanotubes bearing 4-nitro- and 4-(N-morpholinyl)-1,8-naphthalimide DNA intercalators appear as a promising candidate for the treatment of Caco-2.

Heat transfer augmentation in rectangular micro channel covered with vertically aligned carbon nanotubes

An experimental heat transfer investigation was carried out to examine the influence of carbon nanotubes (CNTs) layer deposits on the convective heat transfer performance inside rectangular microchannels. Successful synthesis of vertically aligned CNTs was achieved using a catalytic vapor deposition (CVD) process on a silicon sample substrate. By varying the synthesis time, on average 6μm and 20μm thick layers of CNTs were made with surface roughness of (Sa=1.062μm, Sq=1.333μm) and (Sa=0.717μm, Sq=0.954μm) respectively. The external surface area of the samples increased 7 times compared to the bare silicon chip. The heat transfer performance of each sample was measured inside two rectangular microchannels with cross-section of 125μm×9mm and 200μm×9mm. For the 125μm channel height, the 6μm and 20μm thick layer of CNTs resulted in 12% and 26% increase in pressure drop respectively. The pressure drop obtained from the 200μm channel height show a similar trend with an increase of 6% and 16.4% for 6μm and 20μm CNTs layer thickness respectively. An average heat transfer enhancement of 19% and 74% is obtained inside the 125μm height microchannel with 6μm and 20μm CNTs layer thickness respectively. Whereas, the average heat transfer enhancement of 22% and 62% are obtained inside the 200μm channel with respective CNTs layer thicknesses of 6μm and 20μm. Enhancements are attributed to an increase in surface area and effective thermal conductivity inside the thermal boundary layer. However, the frictional heating (viscous dissipation) of a particular nanostructured sample increases with a decrease in channel height. This difference in channel size results in stronger competition between heat transfer enhancement potential that can be achieved by the deposited surface and the decrease in Nusselt number due to viscous dissipation.

Influence of Microscale Surface Modification on Impinging Flow Heat Transfer Performance

An experimental approach has been used to investigate the influence of a thin layer of carbon nanotubes (CNTs) on the convective heat transfer performance under impinging flow conditions. A successful synthesis of CNT layers was achieved using a thermal catalytic vapor deposition process (TCVD) on silicon sample substrates. Three different structural arrangements, with fully covered, inline, and staggered patterned layers of CNTs, were used to evaluate their heat transfer potential. Systematic surface characterizations were made using scanning electron microscope (SEM) and confocal microscopy. The external surface area ratio of fully covered, staggered, and inline arrangement was obtained to be 4.57, 2.80, and 2.89, respectively. The surface roughness of the fully covered, staggered, and inline arrangement was measured to be (Sa = 0.365 μm, Sq = 0.48 μm), (Sa = 0.969 μm, Sq = 1.291 μm), and (Sa = 1.668 μm, Sq = 1.957 μm), respectively. On average, heat transfer enhancements of 1.4% and − 2.1% were obtained for staggered and inline arrangement of the CNTs layer. This is attributed to the negligible improvement on the effective thermal resistance due to the small area coverage of the CNT layer. In contrast, the fully covered samples enhanced the heat transfer up to 20%. The deposited CNT layer plays a significant role in reducing the effective thermal resistance of the sample, which contributes to the enhancement of heat transfer.

The new MWCNTs–rhenium nanocomposite

AbstractA new nanocomposite was fabricated during the undertaken research efforts, consisting of carbon nanotubes and rhenium nanoparticles. Its structure was examined using transmission electron microscopy (TEM) and the structure modification was confirmed using Raman spectroscopy. Energy dispersive spectroscopy (EDS) was employed to determine the chemical composition of the nanocomposite obtained. Carbon nanotubes with the diameter of 10–20 nm and the length of 10–30 µm, fabricated with the chemical catalytic vapor deposition (CCVD) method, were utilized for the experiment. A fabrication process of the carbon nanocomposite was started with functionalization of multi‐walled carbon nanotubes by oxidization, and then they were placed in a medium containing rhenium precursors. The mixture was further filtered and placed in a heat‐resistant vessel. Rhenium nanocrystals were deposited permanently on carbon nanotubes as a result of a high‐temperature reduction process in the atmosphere of hydrogen and in the shield of inert gas.

Modification of well-aligned carbon nanotubes with dihexadecyl hydrogen phosphate: application to highly sensitive nanomolar detection of simvastatin

The first usage of dihexadecyl hydrogen phosphate (DHP)-modified highly oriented multi-walled carbon nanotube (MWCNTs) forests in a sensor configuration was developed to investigate the electrochemical oxidation and determination of simvastatin (SV) in pharmaceutical dosage forms. Synthesis of well-aligned MWCNTs on a conductive Ta substrate by catalytic vapor deposition technique using a common chemical, ethylenediamine, and without being plasma-aided was reported. The electrochemical behavior and oxidation of SV at the aligned MWCNTs/DHP/Ta electrode were discussed in detail through cyclic voltammetry and differential pulse voltammetry. This modified electrode showed considerably higher electrocatalytic activity for SV than bare Ta electrode or entangled MWCNTs powder electrode, due to presence of the alignment and mutual separation of CNTs. Under the optimal conditions, the A-MWCNTs/DHP/Ta-modified electrode showed a wide linear range from 0.01 to 1 μM with a detection limit of 0.01 nM demonstrating promising results for the future usage in clinical applications.

Different degrees of weak metal–support interaction in Fe–(Ni)/Al 2O 3 catalyst governing activity and selectivity in carbon nanotubes’ production using ethylene

Two Fe-based alumina supported catalysts differing in active phase nature, alumina support origin and methods of synthesis were compared by achieved carbon nanotube (CNT) activity and selectivity in Catalytic Carbon Vapor Deposition reaction using ethylene as a carbon feedstock. Bimetallic Fe–Ni catalyst having 2.5 wt.% of each metals, performed three times an order of magnitude better in terms of CNTs’ yield than the monometallic Fe-based catalyst. Besides, very high selectivity was reached in the case of the preferred catalyst, giving structurally uniformed, multiwalled CNTs with diameters in the range 10–30 nm. The concept of week metal–support interaction (MSI) governing the particular Fe-based catalysts’ behavior was proven by the observed “tip-growth” mechanism of CNTs. However, a various degrees of achieved WMSI in both catalysts, dictated by the addition of the second metal (Ni) and either predefined textural characteristics of the commercial alumina support or the same for the in-house synthesized alumina, is substantial for their different single behavior. Thus, WMSI in the case of calcined Fe/Al 2O 3 sample during its reduction and/or use resulted in metal particles’ mobility and coalescence, being finally materialized as big particles of size above the nano-range. Those particles resulted in very poor activity and selectivity in terms of CNTs’ growth and in addition undergone deactivation by graphene layer deposition. In contrast, somewhat modified interaction has been brought in the case of Fe–Ni/Al 2O 3 catalyst sample after calcinations, keeping optimally sized metal particles stable in the following steps of its reduction/use. In addition, observed encapsulation of metallic particles by growing CNTs, occurring by different magnitudes in examined catalysts, can be understood as directly proportional to the degree of their MSI achieved.

Magnetic amphiphilic composites based on carbon nanotubes and nanofibers grown on an inorganic matrix: effect on water-oil interfaces

New magnetic amphiphilic composites were prepared by the catalytic carbon vapor deposition (CVD) growth of carbon nanotubes and nanofibers using ethanol as carbon source and red mud waste (RM, a by-product of the Bayer process of alumina production) as catalyst and support. Temperature-programmed CVD (TPCVD), analyses by X-ray diffractometry (XRD), Mössbauer spectroscopy, energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetry (TG/DTA), elemental analysis (CHN), superficial area determination (BET), scanning (SEM) and transmission (TEM) electron microscopies and magnetic measurements showed that ethanol reduces the iron ions in the red mud to form magnetic phases, e.g., Fe3O4 and Fe0, and carbon deposits (5-42 wt.%), particularly nanotubes and nanofibers. The combination of the hydrophobic carbon nanostructures with the hydrophilic Al, Si and Ti oxides present in the RM produced amphiphilic materials with excellent interaction with the water-oil interface. Soybean oil or decalin mixtures with water (completely immiscible) were easily emulsified in the presence of the amphiphilic composites. When the composites were added to stable biodiesel-water emulsions, the amphiphilic particles diffused to the interface oil-water. These composite particles were attracted by a magnet, carrying the oil droplets with them and leading to the complete demulsification and separation of the biodiesel from the water.

Structural and Energetic Characterizations of Thin Multi-Walled Carbon Nanotubes Using Adsorption Isotherms

The structural and energetic heterogeneity of thin multi-walled carbon nanotubes (t-MWCNTs) was evaluated from the adsorption of nitrogen and aromatic compounds (benzene, toluene, and m-xylene). The t-MWCNTs was synthesized through the catalytic vapor deposition and characterized by using nitrogen adsorption-desorption isotherm and high-resolution transmission electron microscopy (HRTEM) analyses. The equilibrium adsorption data of aromatic compounds on t-MWCNTs were measured using gravimetric apparatus at three different temperatures (303.15, 313.15 and 323.15 K) and at pressures up to 4.0 kPa. The temperature dependent Toth isotherm model was employed to correlate the experimental adsorption isotherm data. The isosteric heat of adsorption was calculated from van't Hoff equation using the temperature dependent Toth isotherm parameters. The adsorption energy distributions (AEDs) were calculated from adsorption isotherms data of nitrogen and aromatic molecules to investigate the surface energetic heterogeneity of t-MWCNTs. The results of pore size distributions, isosteric heats of adsorption and AEDs revealed that t-MWCNTs have structurally and energetically heterogeneous surface.