Nitrogen-rich Graphitic Carbon Nitride Research Articles

Mediating peroxymonosulfate activation path in Fenton-like reaction via doping different metal atoms into g-C3N5

Peroxymonosulfate (PMS) could be activated by either radical path or non-radical path, how to rationally mediate these two routines was an important unresolved issue. This work has introduced a simple way to address this problem via metal atom doping. It was found that Fe-doped nitrogen-rich graphitic carbon nitride (Fe-C3N5) exhibited high activity towards PMS activation for tetracycline degradation, and the degradation rate was 3.14 times higher than that of Co-doped nitrogen-rich graphitic carbon nitride (Co-C3N5). Radical trapping experiment revealed the contributions of reactive species over two catalysts were different. Electron paramagnetic resonance analysis further uncovered the non-radical activation path played a dominated role on Fe-C3N5 surface, while the radical activation path was the main routine on Co-C3N5 surface. Density functional theory calculations, X-ray photoelectron spectroscopy analysis, and electrochemical experiments provided convincing evidence to support these views. This study supplied a novel method to mediate PMS activation path via changing the doped metal atom in g-C3N5 skeleton, and it allowed us to better optimize the PMS activation efficiency.

Construction of a gelatin aerogel catalyst functionalized with LaCoO3 and g-C3N5 for efficient ciprofloxacin degradation via adsorption and peroxymonosulfate activation

Three-dimensional porous gelatin-based aerogels functionalized with LaCoO3 and nitrogen-rich graphitic carbon nitride (g-C3N5) were successfully fabricated via a freeze-drying approach. Herein, the gelatin-based aerogels served as excellent adsorbents and catalysts activating peroxymonosulfate (PMS) to efficiently degrade ciprofloxacin (CIP) from aqueous solutions. In comparison to the pristine gelatin aerogel (GA), the optimized functionalized aerogel (GA–LCCN-1.5) demonstrated a 17.0% superior CIP adsorption performance. Remarkably, GA–LCCN-1.5 exhibited 95.7% removal efficiency for CIP, attributed to the effective generation of •OH, SO4•−, and 1O2 via PMS activation. In addition, high degradation efficiencies over 84.1% were maintained throughout a broad pH range of 3–9. Notably, GA–LCCN-1.5 demonstrated outstanding stability and reusability, with 93.2% CIP removal efficiency even after five reuse cycles indicating significant promise in real applications. Radical quenching and electron spin resonance (ESR) analysis suggest that CIP degradation was dominated by radical and non-radical routes through GA–LCCN-1.5 catalyzed PMS decomposition. Besides, the plausible CIP degradation mechanisms were systemically analyzed and proposed. The toxicities of CIP and the intermediate by-products were evaluated and reported. The findings of this study and insights demonstrate a facile construction of a biopolymer-based aerogel catalyst for synergistic and efficient PMS activation for the removal of antibiotics in water.

Metal-free g-C3N5 photocatalysts with defect sites as efficient peroxymonosulfate activators for antibiotic removal in aqueous media

Nitrogen-rich graphitic carbon nitride (g-C3N5) has emerged as a promising and fascinating photocatalyst for tackling problems related to antibiotic pollution. Herein, porous O-doped g-C3N5 with N vacancy (g-C3N5-x-O) was fabricated via a facile two-step pyrolysis technique using 3-amino-1,2,4-triazole and oxalic acid as precursors. The sample modified with 2.0 mol.% oxalic acid (CN-2.0) exhibits a porous structure with a specific surface area of 249.78 m2. g−1, 2.77 times greater than that of pristine g-C3N5 (CN-0). In addition, the existence of O-doping and N vacancies in g-C3N5 framework not only promotes charge transfer properties but also suppresses photogenerated electron-hole recombination according to the results of transient photocurrent responses, photoluminescence and electrochemical impedance spectra. The CN-2.0 sample displays the highest photocatalytic activity, which eliminates 77.3% sulfamethoxazole (SMX, 20 mg. L−1) after 60 min irradiation under UV 365 nm light source. The addition of peroxymonosulfate (PMS, HSO5-) significantly accelerates SMX photodegradation rate as well as reduces the influence of pH solution during treatment process. The reactive oxygen species including •O2−, 1O2, SO4•−, •OH, h+ contribute to SMX removal. The efficient degradation of numerous antibiotic classes highlights the possible applicability of g-C3N5-x-O. Interestingly, the catalyst retains its high activity and stability even after four consecutive reuse cycles. The intermediates of SMX degradation were determined and plausible SMX degradation pathways were proposed. Toxicity assessments demonstrated that the overall toxicity of the solution decreased after treatment. This work provides a feasible strategy to design and modulate g-C3N5 photocatalyst activated by PMS for antibiotic removal in wastewater.

Engineering the activity and stability of ZIF-8(Zn/Co)@g-C3N4 nanocomposites and their synergistic action in converting atmospheric CO2 into cyclic carbonates

The development of novel catalytic materials that integrate multifunctional sites has significant implications for expanding the utilization of CO2 resources. However, simultaneously achieving high activity and stability remains a formidable challenge. In this study, a series of ZIF-8(Zn/Co)@g-C3N4 nanocomposites were prepared by employing a thermo-physical compounding strategy that involved the combination of nitrogen-rich graphitic carbon nitride (g-C3N4) nanosheets with ZIF-8(ZnCo). The influences of different compositions of g-C3N4 and ZIF-8(Zn/Co) on the catalyst structure were systematically investigated. Subsequently, the catalytic activities of these nanocomposites towards the cycloaddition reaction between CO2 and epoxide were examined under different conditions. The presence of abundant Lewis base sites in g-C3N4 facilitates CO2 activation, while multiple Lewis acid sites in ZIF-8(Zn/Co) enable efficient epoxide activation. By working synergistically with a co-catalyst, tetrabutylammonium bromide (TBAB), CO2 and epoxides can be efficiently reacted to synthesize the corresponding cyclic carbonates under mild or even atmospheric pressure conditions. The catalytic reaction conditions were optimized, and both the catalyst's recycling performance and the scope of epoxides with various substituents were investigated. The integration of g-C3N4 and ZIF-8(Zn/Co) endows the catalytic material with exceptional structural stability and remarkable catalytic activity, thereby providing a new platform for highly efficient CO2 conversion.

Hydrogen Evolution Activity of Nitrogen-Rich g-C3-xN4+x Synthesized by Solid-Gas Interface Method.

Synthesis of a metal-free carbon nitride (g-C3N4) photocatalyst in the form of nitrogen-rich g-C3-xN4+x derivatives is desirable for efficient solar to hydrogen conversion and remains a challenging task to achieve. Herein we report the development of homogeneous sheets of nitrogen-rich graphitic carbon nitride samples from melamine by a solid-gas interface approach. Using this method, pure g-C3N4 (CN), g-C3-xN4+x under ammonia flow (CN-NH3) and g-C3-xN4+x under nitrogen flow (CN-N2) are prepared. The g-C3-xN4+x (CN-NH3) sample shows better surface conductivity, wide optical absorbance in the visible region, reduced recombination and high electron donor density, and higher performance toward photoelectrochemical hydrogen evolution (HER). The g-C3-xN4+x (CN-NH3) generates a photocurrent of 2.06 μA cm-2, which is 2.5 times higher than that of the pure g-C3N4 (CN) sample (0.85 μA cm-2). It also shows higher photocatalytic water splitting ability compared to the CN and CN-N2 samples, generating 634 μmol g-1 hydrogen without cocatalyst and 1163 μmol g-1 of hydrogen with Pt cocatalyst. Density functional calculations suggest that the progressive band gap reduction with the increase in the N-dopant percentage can be attributed to the gradual increase in the partial π-occupations, which can lead to a significant stabilization of the conduction band minima. The theoretical modeling, however, indicates a saturation in the band gap effect after 75% of N-dopant. The onset potential of g-C3-xN4+x for HER appears at η = 0.43 V in dark and η = 0.34 V vs Ag/AgCl under solar light illumination of 1 sun.

Metal-free g-C3N5 photocatalyst coupling MXenes Ti3C2 for tetracycline degradation: Insight for electron transfer mechanism, degradation mechanism and photothermal effect

At present, nitrogen-rich graphitic carbon nitride (g-C3N5) has emerged as an alternative for traditional graphitic carbon nitride (g-C3N4), due to better visible-light utilization efficiency and abundant surface functional groups. In this paper, a g-C3N5/MXenes (Ti3C2) binary heterojunction was prepared and used as a photocatalyst in environmental remediation. In tetracycline (TC) degradation, g-C3N5/Ti3C2 displayed better performance than those of the reference photocatalysts, including g-C3N5, g-C3N4, Ti3C2 and g-C3N4/Ti3C2. The underlying electron (e-) transfer mechanism was investigated in detail. Besides higher visible-light harvest, better separation efficiency of photo-induced charge carrier and lower surface resistance, an internal-electric-field was established at the interface between g-C3N5 and Ti3C2, and the driving force for e- transfer was 93.9 mV. hole (h+), 1O2, •OH and •O2- were involved into TC degradation, where h+ played a dominating role due to the high e- transfer efficiency. Benefiting from the good photothermal effect, g-C3N5/Ti3C2 could efficiently transfer solar energy to thermal energy, leading to the high temperature of catalyst surface and acceleration of the surface degradation reaction rate. This work provided a possibility to construct a g-C3N5-based visible-light photocatalyst to efficiently degrade the persistent organic contaminants.

Engineered g-C3N5-Based Nanomaterials for Photocatalytic Energy Conversion and Environmental Remediation.

Photocatalysis plays a vital role in sustainable energy conversion and environmental remediation because of its economic, eco-friendly, and effective characteristics. Nitrogen-rich graphitic carbon nitride (g-C3N5) has received worldwide interest owing to its facile accessibility, metal-free nature, and appealing electronic band structure. This review summarizes the latest progress for g-C3N5-based photocatalysts in energy and environmental applications. It begins with the synthesis of pristine g-C3N5 materials with various topologies, followed by several engineering strategies for g-C3N5, such as elemental doping, defect engineering, and heterojunction creation. In addition, the applications in energy conversion (H2 evolution, CO2 reduction, and N2 fixation) and environmental remediation (NO purification and aqueous pollutant degradation) are discussed. Finally, a summary and some inspiring perspectives on the challenges and possibilities of g-C3N5-based materials are presented. It is believed that this review will promote the development of emerging g-C3N5-based photocatalysts for more efficiency in energy conversion and environmental remediation.

From expired metformin drug to nanoporous N-doped-g-C3N4: Durable sunlight-responsive photocatalyst for oxidation of furfural to maleic acid

Following the waste management approach and increasing contamination by the pharmaceutical industry, expired metformin drug, a nitrogen-rich organic scaffold, was employed as a nitrogen dopant for the synthesis of valuable N-doped g-C3N4 under very mild conditions. To this end, various amounts of expired metformin drugs were combined with urea, providing N-doped g-C3N4 with a high N/C ratio, confirmed by X-ray photoelectron spectroscopy (XPS). It was found that the presence of the waste doping agent not only resulted in nitrogen-rich graphitic carbon nitride but also elegantly improved its physical and optical properties such as surface area and the rate of recombination of photogenerated charge carriers, as well as band gap. The photocatalytic potential of prepared samples was evaluated in the oxidation of furfural under sunlight irradiation. In this line, prepared material containing 1 wt% expired metformin drug, which benefits from high surface area and efficient separation of photo-generated electron-hole pairs, was a more efficient photocatalyst to deliver the maleic acid product with high selectivity and yield (98% yield) using hydrogen peroxide as an oxidizing agent. In addition, the photocatalytic system exhibited high stability and could be reused seven times. The key role of hydroxyl and superoxide radicals in the progression of the reaction was established based on control experiments along with proposing the mechanism pathway. Indeed, this study demonstrates a deeper understanding of waste management concepts in chemical applications, particularly in the synthesis of privileged catalysts using green and sustainable approaches.

2D/2D nitrogen-rich graphitic carbon nitride coupled Bi2WO6 S-scheme heterojunction for boosting photodegradation of tetracycline: Influencing factors, intermediates, and insights into the mechanism

A novel two-dimensional 2D/2D Bi 2 WO 6 @g-C 3 N 5 (BiW@CN) step-scheme (S-scheme) heterojunction was designed and fabricated via simple wet chemical approach. The crystal structure, morphology, composition, and optical properties were systematically investigated by multiple techniques. Apparently, BiW@CN heterojunction when compared to bare g-C 3 N 5 and Bi 2 WO 6 has remarkable light-harvesting capability and exhibits better photocatalytic performance toward tetracycline degradation. The excellent enhancement activity of the BiW@CN is due to the formation of S-scheme heterojunction, which not only promotes the spatial charge separation but also endows the reduction power of photogenerated electrons. Notably, the S-scheme charge transfer mechanism was explored by quenching experiments, electron spin resonance , and X-ray photoelectron spectroscopy analysis. Finally, the study proposes possible TC degradation pathways by identifying the transformation products. This research provides a new platform for efficient 2D/2D S-scheme heterojunctions for environmental water pollution treatments. • BiW@CN heterojunction photocatalyst was fabricated via simple wet chemical approach. • Photocatalytic performance of BiW@CN was remarkably boosted under the visible light. • TC degradation pathway was examined through LC-MS identifying transformation products. • The S-scheme charge transfer mechanism of the BiW@CN nanocomposite was corroborated.

Nitrogen-Rich and Porous Graphitic Carbon Nitride Nanosheet-Immobilized Palladium Nanoparticles as Highly Active and Recyclable Catalysts for the Reduction of Nitro Compounds and Degradation of Organic Dyes.

In the present study, we have successfully synthesized nitrogen-rich graphitic carbon nitride (g-C3N4) nanosheets by a simple direct thermal polymerization approach. The synthesized g-C3N4 nanosheets were exfoliated using HCl to make their surface a few nanometers thick. The ultrathin surface was achieved by simply mixing g-C3N4 in 3 M HCl. After that, palladium nanoparticles were uniformly immobilized on the surface of g-C3N4. The synthesized materials were characterized by various physiochemical techniques such as X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Information about morphology and size was obtained through transmission electron microscopy and scanning electron microscopy. The Brunauer–Emmett–Teller surface area, pore volume, and pore diameter were determined using nitrogen adsorption–desorption measurements. The prepared material (Pd/g-C3N4) was utilized as an efficient catalyst for the reduction of hazardous nitroarenes and degradation of organic dyes. The catalyst could be easily recovered through centrifugation and then could be reused multiple times for the further catalytic cycles with a little loss in its catalytic activity. The work presented here illustrates the sustainable anchoring of metal nanoparticles over the surface of nitrogen-rich g-C3N4 nanosheets and could be utilized for different types of catalytic reactions.

Nitrogen-rich graphitic carbon nitride nanotubes for photocatalytic hydrogen evolution with simultaneous contaminant degradation

Graphitic carbon nitride (g-C3N4) has aroused great concern since it applied to the photocatalytic process. However, the inherent shortcomings of bulk g-C3N4, such as small active surface area, low separation efficiency of photogenerated carriers, sluggish charge transport process, etc., result in low-level photocatalytic performance. The rich-nitrogen carbon nitride nanotubes (CNNTs) made by an easy supermolecule self-assembly method could slove these subsisting problems. The CNNTs with unique morphology possess superior separation/migration of photo-excited charge carriers and enhanced photocatalytic performance. Under irradiation with visible light (λ > 400 nm), measured with Pt (3 wt%) as co-catalyst, the CNNTs have a hydrogen evolution rate of 18.06 mmol h−1 g−1 and its apparent quantum yield (AQY) is 12.55% (420 nm). The CNNTs are also applied to degrade antibiotics with simultaneous hydrogen production, providing a method for alleviating energy crisis and environmental pollution issues. The degradation rate of bisphenol A (BPA) is 92% and simultaneously with 13.63 μmol photocatalytic hydrogen generation after irradiation for 5 h.

Porous nitrogen-rich g-C3N4 nanotubes for efficient photocatalytic CO2 reduction

The conversion of carbon dioxide (CO2) into fuels and valuable chemicals using solar energy is a promising method for reducing CO2 emissions and solving energy supply issues. However, the development of inexpensive, efficient and metal-free materials for photocatalytic CO2 reduction is challenging. Herein, we report a facile supramolecular self-assembly strategy for the preparation of porous nitrogen-rich graphitic carbon nitride (g-C3N4) nanotubes with Lewis basicity and a large surface area, which are beneficial for the adsorption of CO2 and, consequently, the enhancement of the photocatalytic CO2 reduction activity. The metal-free porous nitrogen-rich g-C3N4 nanotubes catalyst exhibits a superior visible-light-induced CO2-to-CO conversion rate of 103.6 μmol g−1 h−1, which is 17 and 15 times higher than those of bulk g-C3N4 (6.1 μmol g−1 h−1) and P25-TiO2 (7.1 μmol g−1 h−1), respectively, and exceeds the performance of most metal-free photocatalysts. This work provides new insights into the synthesis of functional groups-modified g-C3N4 with a unique structure for effective photocatalytic CO2 reduction.

Designing an interlayer of reduced graphene oxide aerogel and nitrogen-rich graphitic carbon nitride by a layer-by-layer coating for high-performance lithium sulfur batteries

Herein, reduced graphene oxide aerogel (GA) with 3D interconnected conductive and porous structure was used as a host of sulfur (S@GA cathode). GA was also used together with nitrogen-rich graphitic carbon nitride (GCN) as the interlayer accommodating the soluble lithium polysulfides (LPSs). The interlayer was fabricated by a layer-by-layer coating technique on the flexible and processible carbon fiber paper (CFP) substrate. The interlayer inserted between the cathode and the separator provides a strong lithium polysulfide adsorptivity. Adsorptive LPS species on the interlayer were also investigated by an ex situ X-ray photoelectron spectroscopy. After finely tuned, the as-fabricated LSB using the S@GA cathode with the GA/GCN interlayer exhibits 75% higher specific capacity than the cell without interlayer. It has a low capacity fading of 0.056% per cycle after tested for 800 cycles. Our new design and configuration of LSB may practically be used in high-energy applications since it can effectively address many issues of the current LSBs.

Ultrathin MoS2 sheets supported on N-rich carbon nitride nanospheres with enhanced lithium storage properties

Deciphering the structural and volume changes occurring during electrode reactions in lithium-ion batteries is perhaps a boon for high energy density batteries. Here, we report the synthesis of 3D network of dichalcogenide molybdenum disulfide (MoS2) encapsulated over nitrogen rich graphitic carbon nitride nanosphere (g-C3N4) forming an interconnected and uniform g-C3N4/MoS2 scaffolds. The crystallinity, phase purity, morphological features and elemental composition were evaluated through XRD, FESEM, TEM, HRTEM, BET and XPS analyses. The electrochemical properties of N-rich g-C3N4/MoS2 scaffolds were investigated as potential anode materials for lithium-ion batteries. Electrochemical testing of the g-C3N4/MoS2 constructured electrode delivered reversible capacity of 857mAhg−1at 0.1C rate after fifty cycles and exhibited a high rate performance with reversible capacity of 383mAhg−1 at 10C rate (higher than theoretical capacity of graphite, 372mAhg−1). The superior electrochemical property of g-C3N4/MoS2 is attributed to N-rich carbon support which favors better electronic conductivity, and affords more sites for Li+ ions. The nitrogen rich carbon nitride accommodates volume changes caused during repeated charge/discharges and maintains high structural integrity and specific capacity.

Nitrogen-rich graphitic carbon nitride: Controllable nanosheet-like morphology, enhanced visible light absorption and superior photocatalytic performance

Herein, we reported the synthesis of nitrogen-rich graphitic carbon nitride nanosheets (NRCNNS) material by an NH4Cl assisted chemical blowing approach, where the released gas from the decomposition of NH4Cl prohibited the further polymerization of CN framework and separated the CN layers. A typical two-dimensional morphology with high aspect-ratio was demonstrated by scanning electron microscopy and transmission electron microscopy observation, and the excess amino group on the skeleton was proved by Fourier transform infrared and X-ray photoelectron spectra technologies. Different from the spectral blue-shift in other carbon nitride nanosheets, an enhanced absorption in visible light region was achieved in our NRCNNS due to the N,O-doping level in the band gap. The optimal NRCNNS material with an NH4Cl/melamine mass ratio of 4.0 exhibited a promoted activity (5 times higher than that of the bulky carbon nitride) and reusability for degradation of organic dye under visible light irradiation. Moreover, a possible mechanism was proposed based on the results of valence band spectra and the quenching experiments of active species.

Formation of HxN-rich graphitic carbon nitride network from guanidine carbonate salt by pyrolysis

ABSTRACT Hydrogenated nitrogen-rich graphitic carbon nitride material was successfully synthesized by pyrolysis at 550 °C of an unusual organic precursor molecule, namely guanidine carbonate. The product was characterized in detail using X-ray diffraction, chemical analysis, diverse spectroscopy techniques (Fourier transform infrared, X-ray photoelectron, ultra-violet visible absorption), nitrogen adsorption, and scanning electron microscopy. The results of characterization clearly confirmed the synthesis of a graphitic carbon nitride material (stacking of tri-s-triazine planes) composed of C3.00N4.29H1.59O0.77. In order to understand the mechanism of material formation, products obtained at different temperatures between 200 and 500 °C were systematically investigated. The guanidine carbonate salt precursor is presented to be a promising alternative source for the elaboration of the g-C3N4 material in relation to the classically used cyanamide, melamine or cyanuric-based molecules. Since it is more environmentally friendly and highly soluble in aqueous solvents this new method is definitely strengthening the possibility of process industrialization.

Facile transformation of low cost thiourea into nitrogen-rich graphitic carbon nitride nanocatalyst with high visible light photocatalytic performance

Polymeric nitrogen-rich graphitic carbon nitride (g-C3N4-T) nanocatalyst was synthesized for the first time with a facile approach by directly treating low cost thiourea in air. The g-C3N4-T demonstrated much higher visible light photocatalytic activity than that of g-C3N4 obtained from toxic dicyandiamide, C-doped TiO2 and P25.

Nitrogen-Rich Carbon Nitride Hollow Vessels: Synthesis, Characterization, and Their Properties

Bulk quantities of nitrogen-rich graphitic carbon nitride are synthesized via a facile reactive pyrolysis process with a mixture of melamine and cyanuric chloride as the molecular precursors. Scanning electron microscopy and transmission electron microscopy studies show that micrometer-sized hollow vessels with high aspect ratios have been successfully elaborated without the designed addition of any catalyst or template. The composition of the prepared carbon nitride determined by combustion method is C(3)N(4.91)H(1.00)O(0.22), with the N/C ratio to be 1.64, indicating a high nitrogen content. X-ray diffraction pattern reveals the regular stacking of graphene CN(x) monolayers along the (002) direction with the presence of turbostratic ordering of C and N atoms in the a-b basal planes. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy investigations provide further evidence for graphite-like sp(2)-bonded building blocks based on both triazine and heptazine ring units bridged by 3-fold coordinated nitrogen atoms. The optical properties of the sample are investigated by UV-vis absorption and photoluminescence spectroscopy, which show features characteristic of pi-pi* and n-pi* electronic transitions involving lone pairs of nitrogen atoms. Thermogravimetric analysis curves of the synthesized graphitic carbon nitride hollow vessels show typical weight loss steps related to the volatilization of triazine and heptazine structural units.

Modulation of the crystallinity of hydrogenated nitrogen-rich graphitic carbon nitrides

An hydrogenated nitrogen-rich graphitic carbon nitride, structurally related to the theoretical graphitic phase of C 3N 4, has been synthesized in a bulk well-crystallized form. This new material was prepared by thermal decomposition of thiosemicarbazide up to 600 °C at ambient pressure under nitrogen flow. Its composition was determined by elemental combustion analysis. Powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and C 13 MAS NMR characterizations were performed. This material can be schematically described with a two-dimensional framework and a composition close to C 3N 4.17H 1.12. In this nitrogen-rich material, C 3N 3 voids are fully occupied by water molecules which are strongly trapped into the material. A loss of crystallinity associated with a modification of the thermal behavior is observed when the amount of trapped molecules decreases in the graphitic material, order being damaged both between and in the graphitic planes.

Well-crystallized nitrogen-rich graphitic carbon nitride nanocrystallites prepared via solvothermal route at low temperature

A solvothermal method has been successfully applied to prepare crystalline carbon nitride from C 3N 3Cl 3 and NaN 3 in CCl 4 at 180 °C without any catalyst. The final product was a reddish brown powder. X-ray diffraction pattern indicated that the prepared powder was well-crystallized graphitic carbon nitride. The atomic N/C ratio determined by combustion method was 1.63, indicating a high nitrogen concentration. XPS and FTIR studies showed that graphite-like sp 2 bonded structure existed in the sample. Nanometer scale spherical particles and crinkly lamellas were found in the TEM morphologies.