Sp3 Content Research Articles

Metabolic Engineering for Redirecting Carbon to Enhance the Fatty Acid Content of Synechocystis sp. PCC6803

Metabolic Engineering for Redirecting Carbon to Enhance the Fatty Acid Content of Synechocystis sp. PCC6803

Mixotrophy of Algae: More Algal Biomass and More Biofertilization for Plants

Background: The use of algae as biofertilizers is fast-spreading in order to meet the excessive demands for agricultural products. To achieve this, enough algal biomass needs to be supplied year-round. Hence, algal nutritional components must be optimized through mixotrophic conditions. Materials and methods: Two algal isolates, namely, Phormidium sp. and Synechocystis sp. were tested for their ability to produce mixotrophic growth using different supplementations including molasses, aqueous Lepidium sativum, Trigonella foenum graecum seed extract and liquorice root extract, as well as acetate salt solution. The algae that showed highest growth under optimized mixotrophic conditions was further used in cantaloupe seed growth experiments. GC-MS was also carried out on the biomass of Phormidium on one of the fractions of extract using solvent system to reveal some dominant novel bioactive compounds in algal biomass. Results: The sugarcane molasses significantly enhanced the growth of the two algal strains, followed by Lepidium sativum extract only in case of Phormidium sp. Therefore, it was used in subsequent experiments. All growth parameters for that algae were significantly enhanced by the addition of these nutritional sources with molasses being the best supplement. The Phormidium sp. was rich in its content of chlorophyll, proteins, sugars as well as some novel bioactive compounds as revealed by GC–MS. The germination percentage of seeds treated with Phormidium sp. showed a significant increase over that of control. The different growth-related metabolites of total soluble proteins, total soluble sugars and all photosynthetic pigment contents of the seedlings were all significantly increased using this algal treatment. Discussion: The sugarcane molasses was superior in enhancing the algal growth due to its rich content not only of sugars but also of minerals and nitrogenous compounds. The use of aqueous extracts of seeds of Lepidium sativum enhanced growth significantly more than that of the control set as seeds are rich in proteins, omega-3 fatty acids, phytochemicals and other essential nutrients. In growth experiments carried out on cantaloupe seeds, there was a significant increase in germination percentage as well as all growth parameters due to the rich nutritional content of Phormidium sp. Conclusion: Mixotrophic growth achieved better algal biomass production than autotrophy in the case of Phormidium sp. The use of cheap resources such as sugarcane molasses, which is the waste from the sugar industry, as well as the common herb extract of Lepidium sativum, is a cost-effective approach. The use of this mixotrophically grown blue-green alga as a biofertilizer significantly enhanced plant growth and seed germination, indicating the usefulness of this eco-friendly agricultural strategy for achieving both food security and environmental sustainability.

Anti-corrosion and erosion properties of multilayers with diamond-like carbon and silicon films deposited on low-carbon steel

A multilayer of diamond-like carbon (DLC) and silicon (Si) films were deposited on low-carbon steel (CS) using a combination of bipolar-pulsed magnetron sputtering (MS) and the radio frequency plasma enhanced chemical deposition (RF-PECVD) methods. Spectroscopic techniques such as Raman spectroscopy, synchrotron-based X-ray photoemission spectroscopy (XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to investigate the chemical and structural properties of the film. The mechanical properties were measured using nanoindentation and nano-scratch testers. The films' electrochemical performance and corrosion behavior were evaluated in the 3.5 wt% NaCl solution at room temperature. The erosion resistance of the films was studied under the sand jet impingement apparatus. The results indicate that the 2 Si-layers in the DLC film and CS substrate increase the C‒sp3 content at the DLC film surface resulting in high mechanical hardness. The adhesion of the DLC film on the CS substrate was also improved by adding the Si layer between the CS substrate and DLC film. Consequently, multilayer Si/DLC film resists the elastic deformation of films caused by graphitization.

Effect of hydrogen plasma treatment of nanodiamond on the tribological properties of polytetrafluoroethylene-based nanocomposite coating

ABSTRACT Carbon atom recombination and etching of the surface of nanodiamond (ND) by hydrogen plasma and their effects on the dispersion and the tribological properties of a polytetrafluoroethylene (PTFE) nanocomposite coating were investigated. The surface-modified ND samples subjected to plasma treatment were characterized using FESEM, HRTEM, Raman spectroscopy, FT-IR spectroscopy and XPS. The results showed that the plasma treatment facilitates etching and recombination of the ND surface and modifies the crystallinity of the graphitic amorphous carbon. The tribological properties of the PTFE-based nanocomposite coatings prepared with the modified ND depended on the content of sp 3 -bonded carbon on the surface and the crystallinity of the ND. Hydrogen plasma treatment caused a significant improvement in the dispersion and tribological properties of the PTFE/ND nanocomposite coating due to surface modification of the ND.

Bayesian-Optimization-Assisted Laser Reduction of Poly(acrylonitrile) for Electrochemical Applications.

Laser reduction of polymers has recently been explored to rapidly and inexpensively synthesize high-quality graphitic and carbonaceous materials. However, in past work, laser-induced graphene has been restricted to semiaromatic polymers and graphene oxide; in particular, poly(acrylonitrile) (PAN) is claimed to be a polymer that cannot be laser-reduced successfully to form electrochemically active material. In this work, three strategies to surmount this barrier are employed: (1) thermal stabilization of PAN to increase its sp2 content for improved laser processability, (2) prelaser treatment microstructuring to reduce the effects of thermal stresses, and (3) Bayesian optimization to search the parameter space of laser processing to improve performance and discover morphologies. Based on these approaches, we successfully synthesize laser-reduced PAN with a low sheet resistance (6.5 Ω sq-1) in a single lasing step. The resulting materials are tested electrochemically, and their applicability as membrane electrodes for vanadium redox flow batteries is demonstrated. This work demonstrates electrodes that are processed in air, below 300 °C, which are cycled stably over 2 weeks at 40 mA cm-2, motivating further development of laser reduction of porous polymers for membrane electrode applications such as RFBs.

The Study of Surface Structure and the Tribological Property of DLC-Modified NBR Elastomers Using DC-MS

The DLC film was prepared on a nitrile rubber (NBR) elastomer by DC magnetron sputtering (DC-MS), and the sp3 ratio of the DLC film was adjusted by changing the negative bias voltage applied to the substrate. The microstructure, composition, and tribological properties of the DLC films deposited on NBR substrates were systematically investigated. The results reveal that the DLC film on the NBR surface can protect the NBR and reduce the surface roughness of the NBR. While the bias voltage ranges from 0 V to −150 V, the content of sp3 increases with an increase in the negative bias voltage. The viscoelasticity and roughness of the NBR substrate will greatly affect the DLC film’s adhesion strength and tribological behavior.

Parameters study of carbon bombardment step for enhanced adhesion of thick DLC coating deposited by cathodic arc evaporation

The main limitation for the deposition of thick (> 5 μm) DLC coatings is to achieve adhesion to the substrate. In the present work, the adhesion of thick (~20 μm) amorphous carbon coatings was analyzed considering the combination of metallic chromium as bond layer and a carbon bombardment step before the deposition of the functional coating. The carbon bombardment step was included to generate an interfacial structure composed by a mixing layer of Cr and C and a carbon transition layer rich in sp2 bonds. The complete deposition process was made by cathodic arc and the substrate was nitrided steel. Different sets of parameters were used during the carbon bombardment to change the interfacial structure and to analyze the effect on adhesion. The parameters evaluated were the bias voltage, duration, cathode current and temperature. The adhesion of a-C layer was assessed by scratch tests and the interface structure was evaluated by scanning transmission electron microscopy (STEM). Results indicate that a lower bias voltage possibly increased the sp3 content of the carbon transition layer, mitigating the negative impact of a thicker carbon transition layer. Moreover, an increase in the carbon cathode current may increase the adhesion, possibly by an increase in the thickness of the mixing layer. Finally, improved adhesion was achieved when the temperature of the bombardment was reduced. A diagram of expected behavior for the adhesion (in terms of critical load during scratch tests) as a function of carbon transition layer thickness and sp-bonds was proposed based on the available results.

Microstructure, mechanical and tribological properties of Ti doped ta-C films deposited by a hybrid coating system

Ti doped ta-C films were deposited by a hybrid coating system with filtered cathodic vacuum arc and pulsed DC magnetron sputtering. The microstructure, mechanical and tribological properties of ta-C: Ti films were investigated. Results showed that the Ti content in the films linearly increased from 0 to 19.9 at. % by increasing the Ti target current from 0 to 2 A. Without and with small amount of Ti doing, ta-C films presented typical amorphous characteristic. TiC phase was formed in the film at Ti content of 5.5 at. %, and as the Ti content further increased, the microstructure of the films gradually transformed to nanocomposite structure, where TiC nanocrystalls were embedded in amorphous carbon matrix. The sp3 bonding fraction was decreased with increasing Ti content, accordingly, the hardness and residual stress of films also decreased with diminishing sp3 content. In addition, the Ti doping had a positive impact on the adhesion force between films and substrates. ta-C film with Ti doping content of 5.5 at. % had the lowest friction coefficient and the lowest wear rate under different friction temperatures, corresponding to 0.09 and 3.6 × 10−8 mm3/N·m at room temperature, and 0.25 and 22.5 × 10−8 mm3/N·m at 400 °C, respectively, which was mainly attributed to the relative high hardness, lower residual stress, good adhesion of the film.

Enhancing docosahexaenoic acid production of Schizochytrium sp. by optimizing fermentation using central composite design.

Docosahexaenoic acid (DHA) can improve human and animal health, particularly including anti-inflammatory, antioxidant, anticancer, neurological, and visual functions. Schizochytrium sp. is a marine heterotrophic protist producing oil with high DHA content, which is widely used in animal and food production. However, different fermentation conditions have intensive impacts on the growth and DHA content of Schizochytrium sp. Thus, this study aimed to enhance the DHA yield and concentration of Schizochytrium sp. I-F-9 by optimizing the fermentation medium. First, a single-factor design was conducted to select a target carbon and nitrogen source from several generic sources (glucose, sucrose, glycerol, maltose, corn syrup, yeast extract, urea, peptone, and ammonium sulfate). The Plackett-Burman design and the central composite design (CCD) were utilized to optimize the fermentation mediums. Schizochytrium sp. in 50-mL fermentation broth was cultured in a 250mL shake flask at 28°C and 200rpm for 120h before collecting the cell pellet. Subsequently, the cell walls were destroyed with hydrochloric acid to extract the fatty acid using n-hexane. The DHA content was detected by gas chromatography. The single-factor test indicated that glucose and peptone, respectively, significantly improved the DHA content of Schizochytrium sp. compared to the other carbon and nitrogen sources. Glucose, sodium glutamate, and sea crystal were the key factors affecting DHA production in the Plackett-Burman test (P = 0.0247). The CCD result showed that DHA production was elevated by 34.73% compared with the initial yield (from 6.18 ± 0.063 to 8.33 ± 0.052g/L). Therefore, the results of this study demonstrated an efficient strategy to increase the yield and content of DHA of Schizochytrium sp.

Effect of the bias-graded increment on the tribological and electrochemical corrosion properties of DLC films

Diamond-like carbon (DLC) films with bias-graded increments of 5 V, 10 V, and 20 V were prepared by adjusting the substrate bias voltage in a high-power pulsed magnetron sputtering system (HPPMS). The microstructural, mechanical, tribological, and electrochemical corrosion properties of DLC films were systematically investigated. In this work, the sp 3 content in the DLC film with a constant bias of −200 V was the highest, and the sp 3 content in the bias-graded DLC film exhibited a gradient increasing trend. Bias-graded DLC films had lower hardness, elastic modulus and residual stress than DLC film with a constant bias of −200 V. With a decrease in bias-graded increment, the ratio of hardness to elastic modulus increased. Friction and wear tests demonstrated that the wear resistance of the DLC film was related to the hardness, residual stress and ratio of the hardness to the elastic modulus. The wear rate decreased with decreasing bias-graded increment, and the DLC film with a bias-graded increment of 5 V had the lowest friction coefficient and wear rate, which were 0.077 and 6.74 × 10 −7 mm 3 /Nm, respectively. The polarization curve results revealed that the DLC film with constant bias had the highest corrosion potential and corrosion current density. As the bias-graded increment increased, the corrosion potential and corrosion current density showed an increasing trend. Combined with the electrochemical impedance spectroscopy results, the bias-graded DLC films with bias-graded increments of 5 V and 10 V exhibited better corrosion resistances. • Bias-graded DLC films were prepared in HPPMS system. • Gradient structure achieved the balance between the residual stress and the content of sp 3 . • Coating DLC film can significantly improve the tribological and electrochemical corrosion properties of the substrate.

Corrosion Properties of DLC Film in Weak Acid and Alkali Solutions

As an important joint material, tantalum (Ta) needs to be studied intensively in terms of wear and corrosion resistance. Two films of Ta/Ti/DLC (diamond-like carbon) (referred to as TD film) and Ta/Ti/TiN/Ti/DLC (referred to as TTTD film) were prepared by magnetron sputtering technology, and their electrochemical corrosion performance in lactic acid and sodium bicarbonate solutions was also investigated. The morphology observation, electrochemical corrosion experiment, and static contact angle measurement were carried out using a scanning electron microscope, electrochemical workstation, and a contact angle meter. This paper mainly discusses and analyzes the corrosion influencing factors and corrosion mechanisms of these two films under two different environments. The 20-day immersion experiments show that the TD film in both solutions results in severe surface corrosion due to its loose structure and many internal defects. In contrast, the surface of the TTTD film with a dense structure, a multilayer structure, and a thicker thickness is not corroded under the same conditions. The electrochemical corrosion experiments show that the corrosion resistance of the TD film is worse than that of the Ta substrate, while the TTTD film has the strongest corrosion resistance, improving the corrosion resistance of the Ta substrate. Although the TD film had a higher sp3 content than the TTTD film, it does not provide protection to the Ta substrate due to increased structural defects in the TD film. The results of the contact angle show that the contact angle of the TTTD film is smaller than that of the TD film in both solutions. However, the TTTD film has the lowest roughness and the densest structure, and thus the TTTD film is more resistant to corrosion. It is finally concluded that the surface morphology and internal structure of the films are the main factors affecting corrosion resistance. This provides an important reference for the application of DLC film in weak alkaline and weak acid environments.

Investigate the Potential Renewable Energy of Microalgae Spirulina sp Using Proximate Analyzer, SEM-EDX, and Thermogravimetry

Microalgae Spirulina sp which has been cultivated by the Brackishwater Aquaculture Development Center, Situbondo Indonesia were tested for their potential energy performance using proximate analyzer, SEM-EDX, and thermogravimetry. The proximate analyzer showed volatile matter (VM), fixed carbon (FC), moisture, ash content (AC), total sulfur of microalgae Spirulina sp 68.15, 12.57, 11.22, 8.06, and 0.67 (wt%, ar), respectively, and the gross calorific value (GCV) is 4971 kcal/kg (dry basis). SEM-EDX test showed the morphology and chemical content of Spirulina sp. The content of microalgae Spirulina sp is dominated by carbon (C) and oxygen (O), then followed by chlorine (Cl), sodium (Na), potassium (K), sulfur (S), magnesium (Mg), and phosphorus (P). Thermogravimetry pyrolysis test of microalgae Spirulina sp resulted thermogravimetry (TG) analysis and derivative thermogravimetry (DTG) analysis curve, which is divided into three different steps. The moisture of microalga Spirulina sp was vaporized at the first step, started at 27°C, and finished at 173°C with a decomposed mass of about 13.81% of the total initial mass. The second step began at the end of vaporize moisture at about 173°C and ended at around 618 °C. The gasification process occurred in volatile matter content and resulted mass loss of about 57.9% of Spirulina sp total mass. The last step showed the process of gasification of residual substances, started at the end of the volatile matter step, 618°C, and stopped at 995°C with a decomposed mass of 24.6% from total mass.

Coal tar-derived conductive pigment/polyvinylidene fluoride composite for Joule heating

The fast-increasing demand for high-performance carbon conductive paints has motivated the use of inexpensive precursors and easy-to-manufacture methods to scale up production. The performance of carbon conductive paints highly depends on the precursor types, carbonization conditions and the coordination between carbon pigment and binder. This work investigated the effect of precursors (by-products of coking industry including coal tar pitch, anthracene oil, naphthalene oil, and washing oil) on the structure and properties of carbon pigment, as well as the influences of binders polyvinylidene fluoride (PVDF), styrene-butadiene emulsion, and acrylic emulsion on the electrothermal properties and adhesion of carbon paint coating. The conductive pigment prepared from coal pitch has nano-sheet structure, high sp2 content, large sp2 cluster size and high disordered structure, resulting high carrier concentration and mobility, and low volume resistivity. The carbon conductive coating fabricated from coal pitch-based pigment and PVDF (PC-PVDF) has good electrothermal properties, excellent stability, low volume resistivity, good adhesion and corrosion resistance. The electrical conductivity of carbon-PVDF composites prepared from coal tar pitch, anthracene oil, naphthalene oil, and washing oil as precursors were 15.7, 3.0, 4.4, and 4.0 S/m, respectively. Coal pitch-derived conductive pigment-PVDF carbon coating exhibits excellent Joule heating performance, i.e., up to 147 °C at 20 V when heating at 122 °C/min, uniform temperature distribution, and excellent reusability. This work demonstrates the potential application of coal pitch-based pigment-PVDF coating for Joule heating.

The mechanics and design of a local crystallization of amorphous for carbon material by molecular dynamics simulation

Achieving high strength and plasticity by means of microstructure manipulation of three-dimensional carbon material attracts researchers’ attention. This work is primarily on the influence of sp2 content at micro and molecular level on mechanical properties by molecular dynamics simulation. Additionally, the influence of interfaces has been investigated by three multi-nanocapsule pillars assembled with the equiaxed amorphous models. The model that has the best fit between strength and plasticity we obtained is the amorphous model with 100% multi-layer nanotubes fragments, and with no interfaces. We found that the rotating and folding of fragments are the main microscopic deformation mechanisms of amorphous carbon materials with sp2 fraction decreasing attributed to the breaking of covalent bonds, which has also been verified in experiment. The rotation of the nanocapsule and the migration of the interface contribute more in the condition of the existence of interfaces in the amorphous carbon material.

In-situ monitoring of microwave plasma-enhanced chemical vapour deposition diamond growth on silicon using spectroscopic ellipsometry

The quality of polycrystalline diamond films is heavily dependent on the nucleation and early stages of growth, making the ability to monitor these early stages highly desirable. Spectroscopic ellipsometry (SE) allows for real-time monitoring of the thickness, composition, and morphology of films with sub-nanometre precision. In this work, ex-situ SE spectra were used to develop an optical model for film characterisation, which was then applied to in-situ data. The coalescence of individual crystallites into a single film was observed through a parabolic decrease in void content followed by peaks in sp2 content and surface roughness. These observations were validated using ex-situ Raman spectra and AFM images of samples grown for durations between 5 and 30 min. The model was also used to investigate the impact of varying the methane concentration, finding that a higher methane fraction resulted in earlier coalescence and a higher peak in sp2 content. This work demonstrates that SE is a powerful tool for monitoring and optimisation of the critical early stages of polycrystalline diamond growth.

Experimental Study of Diamond-like Carbon Film on Aermet100 Steel and First-Principles Calculation of Interfacial Adhesion.

Three different types of surface-modified layers of N, C, and N+C are successfully prepared on AerMet100 steel by plasma-assisted thermochemical treatment, and diamond-like carbon (DLC) films are formed on the top surfaces of the latter two. The results show that the DLC films produced by prenitriding and then carburizing (N+C) exhibit a smoother and finer morphology and higher sp3 content than that without prenitriding (C). In addition, the wear resistance of the N+C specimen with a high hardness nitrided layer as the support for the outermost DLC films is superior to that of the C specimen. In view of the catalytic effect of the Fe3C phase on the growth of DLC films, the interfacial properties of Fe3C(001)/diamond(111) are investigated using first-principles calculations. On the basis of the most preferred Fe-terminated HCP site model, the effects of alloyed cementite (Fe2MC) on interfacial adhesion of Fe2MC(001)/diamond(111) are also investigated. Furthermore, the mechanisms of interfacial adhesion for two representative dopings (Zr weakened and V enhanced) are revealed in detail. These results are expected to provide a potential promising means for future experimental works on the preparation of high-performance DLC films on alloy steel surfaces by plasma carburizing.

Microalgae as a promising structure ingredient in food: Obtained by simple thermal and high-speed shearing homogenization

As a biological resource, microalgae are considered promising functional food components due to their balanced composition and various nutritional components. Its function in food is not limited to health but also plays a structural role in food. Therefore, research of the rheological properties of microalgae is vital. Thermal pre-treatment (TP) and high-speed shearing homogenization (HSH) are common processing methods in food processing. Here, we studied the effects of TP and HSH on the rheological properties, microstructure, polysaccharide content, and monosaccharide composition of Synechococcus sp. PCC 7002 and Spirulina platensis. The combined of TP and HSH treatment endowed the Spirulina platensis suspensions with shear thinning characteristics and enhanced gel characteristics (G'> G″), they also led to the breaking of Spirulina platensis cells, thus soluble polysaccharides such as polysaccharides bound to cell walls were released, which greatly increases the viscosity of the suspensions. This study provides a scientific basis for the food of microalgae and the change of food rheology containing microalgae. • A new method to improve rheological properties of microalgae. • After treatment, the viscosity was increased by 30–200 times. • Synechococcus sp. PCC 7002 has the potential as one kind of food thickener. • This study lays a foundation for the food of microalgae.

Investigation of Vacuum Arc-Deposited ta-C and ta-C:N Thin Films on Silicon and Stainless-Steel Foil Substrates Using Raman Spectroscopy

In this paper, we investigated the vacuum arc-deposited tetrahedral amorphous carbon (ta-C) and nitrogen-doped ta-C (ta-C:N) thin films grown on silicon and stainless-steel foil substrates by the visible Raman Spectroscopy. We found that carbon films grown on silicon surfaces prefer more sp3 hybridized carbon compared to the stainless-steel foil, which prefer more sp2 hybridized carbon even though the films are grown concurrently under the same conditions. The impact energy of plasma ions modifies the interfacial layer formation, giving a strong dependence of the sp2/sp3 ratio with the substrate bias, behaving differently for different substrates. However, nitrogen doping in amorphous carbon thin films helps to increase sp2 contents uniformly on both the surfaces for a fixed substrate bias. Understanding such interfaces are of interest for many electronic, optoelectronic, and energy storage devices as these interfaces get buried and can influence the properties significantly.

Effect of doping elements to hydrogen-free amorphous carbon coatings on structure and mechanical properties with special focus on crack resistance

The doping of amorphous carbon is one way of specifically modifying its properties. The present work is a contribution to understand the effect of dopant selection on structure, mechanical properties and crack resistance of hydrogen-free tetrahedral amorphous carbon (ta-C) coatings. For this purpose, nonmetallic (B, Si) and metallic (Mo, Fe, Cu) dopants were selected. The coatings were produced by the Laser-Arc technique and investigated by Raman spectroscopy, transmission electron microscopy, nanoindentation, bending, and scratch tests. It was found that doping generally affected the sp2 content and cluster size of the sp2 carbon phase, and thus hardness, Young's modulus, and intrinsic compressive stresses, but also the defect content and the crack resistance. The addition of metallic dopants led to an increase and clustering of the sp2-bonded carbon and, consequently, to a significant reduction in hardness and Young's modulus. This effect was much less pronounced when doping with non-metallic elements. The failure behavior changed toward higher ductility and crack resistance when metals were added. The crack resistance was found to be directly dependent on the H3/E2 value, with H3/E2 > 0.2 leading to a more brittle behavior with unstable crack propagation, while at H3/E2 < 0.2 the material was more ductile and exhibited stable crack propagation and thus higher crack resistance.

Effect of topological non-hexagonal rings and Stone Wale defects on the vibrational response of single and multi-layer ion irradiated graphene

Present study explores the observation of topological non-hexagonal rings (NHR) and Stone Wale (SW) defects by Raman experiments in both single (SLG) and multi-layer graphene (MLG) after they are irradiated with 100–300 eV Ar ions. Although predicted by theoretical studies, here it is experimentally shown that graphene SW/NHR defects have a signature in Raman. Broad bandwidth of the pertinent Raman features suggests the presence of more than one SW/NHR defect mode, in agreement with the DFT studies. Variations in the SW/NHR related Raman mode intensities demonstrate the annihilation of these topological defects at higher energies. Behavior of Raman allowed G and 2D excitations, as well as the disorder-activated D, D’ and G* lines, has also been investigated in SLG and MLG. These indicate an evolution of defects in graphene with ion irradiation, as well as presence of a transition state beyond which the Raman modes are dominated by a rise in sp3 content. Correlation of these aspects with the SW/NHR Raman provide significant insight into ion induced evolution of graphene. The direct observation of SW/NHR defects by Raman spectroscopy could be important in promoting exploration of rich topological aspects of Graphene in various fields.