Structure Of rGO Research Articles

Fabrication of rGO/SrSeO4 nanocomposite as an electrode material with enhanced specific power for supercapacitor applications

Fossil fuels are the major source of energy in the world, which are being depleted day by day. Fossil fuels are also polluting the environment by releasing greenhouse gases such as carbon dioxide. To overcome environmental pollution as well as energy crisis, exploration of new ways of storing energy is the need of the time. In the presented work, reduced graphene oxide/Strontium selenate nanocomposite has been synthesized as an electrode material for energy storage devices. The structure of rGO/ SrSeO4 nanocomposite was confirmed by x-ray diffraction while the morphology was investigated by scanning electron microscopy. The electrochemical measurements, such as cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy and cyclic stability, were also carried out. The synthesized nanocomposite showed excellent specific power of 684.16 W/kg with 3.67 Wh/kg specific energy, which is significantly much better than already reported metal selenide materials.

Graphene-Wrapped FeOOH Nanorods with Enhanced Performance as Lithium-Ion Battery Anode

FeOOH nanorods (NRs) wrapped by reduced graphene oxide (rGO) were fabricated using a facile solvothermal method. When used as anode materials for lithium-ion batteries (LIBs), the FeOOH NRs/rGO composites show a higher capacity (490[Formula: see text]mAh g[Formula: see text] after 100 cycles at a current density of 100[Formula: see text]mA g[Formula: see text] and better rate capability than pure FeOOH NRs. The enhanced electrochemical performance can be ascribed to the hybrid structure of FeOOH and rGO. On one hand, the introduction of rGO can improve electronic conductivity and reduce charge-transfer resistance for electrode materials. On the other hand, the distinctive structure (FeOOH NRs surrounded by flexible rGO) can effectively buffer large volume change during the Li[Formula: see text] insertion/extraction process. Our work provides a feasible strategy to obtain high-performance LIBs.

Aryne cycloaddition reaction as a facile and mild modification method for design of electrode materials for high-performance symmetric supercapacitor

Covalent modification of graphene-based materials can be considered as one of the most promising methods for tailoring their electrochemical properties and extending their application as electrode materials for supercapacitors. In this contribution, we report a facile and mild approach for the covalent functionalization of reduced graphene oxide (rGO) via aryne cycloaddition using pseudocyclic iodoxoborole as an aryne source. The structure and chemical composition of the functionalized rGO (f-rGO) were assessed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), ultraviolet–visible (UV–vis) spectrophotometry, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), which revealed the negligible influence of covalent modification on the rGO structure. Transmission electron microscopy (TEM) imaging showed an increase of the interlayer distance from 0.38 to 0.46 nm upon functionalization. The electrochemical performance of f-rGO material was studied by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques in 2 M KOH aqueous solution as the electrolyte. Under optimized conditions, the f-rGO displayed a high specific capacitance of 297 F g−1 at a current density of 1 A g−1, which is much higher than that of unmodified rGO (170 F g−1 at 1 A g−1). Therefore, the f-rGO was used to construct a symmetric supercapacitor device, exhibiting an energy density of 6.7 Wh kg−1 at a power density of 685.8 W kg−1. The device exhibited good cycling stability and ability to maintain about 96% of the initial capacitance value after 10,000 cycles. Furthermore, two symmetric supercapacitor devices were successfully applied to power a home-designed windmill device for 3 s. The results obtained in the present study highlight the importance of graphene functionalization as an effective route to fabricate rGO-based materials with enhanced properties in energy storage devices.

Robust and conductive mesoporous reduced graphene oxide-silica hybrids achieved by printing and the sol gel route

Reduced graphene oxide (rGO) scaffoldings are used as templates to create lightweight 3D rGO/silica and rGO/silico-aluminate hybrids by a simple impregnation route and the sol-gel method. The printed rGO assemblies are infiltrated by the corresponding alkoxide precursor solution and gelled by exposure to ammonia vapours, producing an hybrid replica of the rGO structure. The hybrids show a significant prevalence of mesopores, with total porosity above 94 %, density of ∼ 0.1 g⋅cm−3 and high specific surface area (≥ 190 m2⋅g−1). As a result, the 3D composite materials show enhanced water adsorption capacity and hydrophilicity, display compressive strengths in the range 0.1 – 0.4 MPa, which scale with the proportion of silica (or Al-modified silica) on the hybrid scaffold, and electrical conductivities are above 60 S⋅m−1. These properties are very attractive for applications in the removal of pollutants, water filtering, catalysis, drug delivery, or energy production and storage.

Fire retardant cellulose aerogel with improved strength and hydrophobic surface by one‐pot method

AbstractBio‐based materials with multifunctional performance are getting immense attention nowadays for their environment friendly and renewable character. Inspired by toughening effect of graphene nanosheets and borate chemistry, a simple in‐situ borate crosslinking in water and freeze‐drying method was employed to fabricate a fire retarded bio‐based aerogel. The structure of the material was evaluated and analysis by SEM, XRD, FTIR, Raman and XPS. Importantly, the bio‐based aerogel has improved strength and adsorption properties due to unique structure. The compressive strength of rGO(reduced graphene oxide) + CMC (carboxymethyl cellulose) aerogel could reach 128 ± 2.1 kPa which is five times that of neat CMC aerogel. The bio‐based aerogel can load more than 2500 times of self‐weight. The adsorption capacity for organic solvents and oil of rGO+CMC aerogel is also greatly improved by a little rGO (1%) introducing due to its unique porous structure and hydrophobic nature of rGO. Additionally, rGO+CMC aerogel is also found fire resistant with relatively low thermal conductivity due to the borate and GO introduction.

Influence of reduced graphene oxide (rGO) on phase development and porosity of SiOC/rGO ceramic composites

Ceramic materials based on silicon oxycarbide (SiOC) and reduced graphene oxide (rGO) were produced by polymer pyrolysis and evaluated in terms of phase development and porosity. Carbonaceous phase, initially prepared from graphite oxide, was incorporated into silicone dihydroxy terminated in different amounts (0, 5, 15 and 25 wt%) and submitted to pyrolysis at 1500 °C to obtain SiOC/rGO ceramics. Higher ceramic yields and more thermally stable materials were obtained after rGO addition, whose results were associated to the chemical interaction degree between rGO and polymer structure. Cgraphite and SiC phases were generated in rGO-containing ceramics and a mixture of α- and β-SiC was achieved from 15 wt% rGO, enhancing their crystallinity with increasing of rGO content. Porosity features were influenced by the carbonaceous phase amount and different rGO-polymer interaction degrees. SiOC/rGO ceramics demonstrated desirable structural characteristics for future investigations in electrical and/or electrochemical applications.

Bismuth Subcarbonate Decorated Reduced Graphene Oxide Nanocomposite for the Sensitive Stripping Voltammetry Analysis of Pb(II) and Cd(II) in Water.

In this paper, bismuth subcarbonate (BiO)2CO3-reduced graphene oxide nanocomposite incorporated in Nafion matrix ((BiO)2CO3-rGO-Nafion) was synthesized and further applied, for the first time, in the sensitive detection of Pb(II) and Cd(II) by square-wave anodic stripping voltammetry (SWASV). The as-synthesized nanocomposites were characterized by energy-dispersive spectroscopy (EDS), Raman spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). (BiO)2CO3 composite plays a key role in the improvement of the detection sensitivity, which can form multicomponent alloy with cadmium and lead. Additionally, the unique structure of rGO can enlarge the surface area and provide abundant active sites. Moreover, Nafion incorporation in the nanocomposite can effectively increase the adhesion and mechanical strength of the film, and further improve the preconcetration ability due to the cation-exchange capacity of its abundant sulfonate groups. As expected, the (BiO)2CO3-rGO/Nafion nanocomposite-modified glassy carbon electrode ((BiO)2CO3-rGO-Nafion/GCE) achieved low detection limits of 0.24 μg/L for Pb(II) and 0.16 μg/L for Cd(II), in the linear range of 1.0–60 μg/L, and showed some excellent performance, such as high stability, good selectivity, and sensitivity. Finally, synthetic water samples were prepared and further used to verify the practicability of the (BiO)2CO3-rGO-Nafion/GCE with satisfactory results.

Synthesis of Reduced Graphene Oxide as a Support for Nano Copper and Palladium/Copper Catalysts for Selective NO Reduction by CO.

Copper and palladium/copper nanoparticles supported on reduced graphene oxide catalysts were synthesized and evaluated for the selective NO reduction by CO. The catalysts were characterized by XRD, nitrogen adsorption–desorption, TGA, XPS, TPR, in situ XRD, STEM, and HRTEM. The STEM and HRTEM results showed high metal oxide dispersions on the rGO. XPS results showed the presence of Cu and Pd oxide species. The reduction of copper supported on the rGO occurred in two steps for CuOx/rGOc, while that for CuOx-PdOy/rGOc occurred in one step for temperatures lower than 350 °C. Noteworthy is that the in situ XRD results showed that the rGO structure was not affected after reduction at 350 °C. The in situ XRD of reduction revealed the appearance of new phases for copper during the reduction. The catalysts were evaluated in NO reduction by CO. The tests showed that the reduced catalysts presented high performance with NO conversions and N2 selectivity above 85% at 350 °C.

Anode Photovoltage Compensation‐Enabled Synergistic CO2 Photoelectrocatalytic Reduction on a Flower‐Like Graphene‐Decorated Cu Foam Cathode

AbstractAn interconnected and hierarchically structured electrode composed of a Cu nanoparticle‐modified flower‐like reduced graphene oxide‐decorated copper foam (Cu NP/f‐RGO/CF) is crafted and exploited for photoelectrocatalytic (PEC) reduction of CO2 in a TiO2 nanotube photoanode‐driven PEC cell. Anode photovoltage compensation confers a more negative cathode potential for CO2 reduction, thus leading to a synergistic effect between photocatalysis (PC) and electrocatalysis (EC). CO2 reduction rate under PEC condition is 5.4× higher than that of the simple sum under PC and EC processes. The well‐defined flower structure of RGO in the CF scaffold effectively prevents its self‐agglomeration, which increases its adsorption towards CO2 with improved electron‐transfer kinetics due to the 3D interconnected structure with abundant electron transfer pathways. DFT calculations further reveal the absorption and activation of CO2 on Cu NP/f‐RGO capitalize on the CC bond with RGO and OCu bond with Cu NPs, thereby leading to a bended and stretched structure. The enhanced CO2 adsorptivity and activation on the hierarchical Cu NP/f‐RGO/CF electrode significantly improve CO2 reduction and facilitate the conversion of C1 products to high‐order products. This research highlights the great prospect of anode photovoltage compensation enables synergistic photoelectrocatalysis and 3D hierarchical electrode for CO2 drastic reduction into high‐order products.

Construction of interconnected SiC particles attached rGO structure in epoxy composites to achieve significant thermal conductivity enhancement

Reduced graphene oxide (rGO) has been excellent three-dimensional network carries due to unique flexibility and high thermal conductivity. However, restricted by excellent electrical property of rGO, it remains blocking to fabricate high performance polymer composites applied in the electronic packaging field. In this work, a novel GO-assisted method was used to prepare different rGO@SiC structure as efficient heat pathways in polymer composites achieving desirable performance. The as-prepared epoxy composite, at a filler loading of 30 wt% and SiC particles of 600 nm, exhibited not only a high thermal conductivity (1.02 W/mK) but also the lowest electrical conductivity (1.18 × 10−12 S/cm). An effective medium theory model (EMT) was constructed to perfectly predict the thermal conductivity of the composites and precisely calculate the interfacial thermal resistance. The research provides a creative insight to the design of rGO structure and high-performance composites with a bright application prospect in advanced thermal managing materials.

Hydrodechlorination of carbon tetrachloride with nanoscale nickeled zero-valent iron @ reduced graphene oxide: kinetics, pathway, and mechanisms.

In recent years, carbon tetrachloride (CT) has been frequently detected in surface water and groundwater around the world; it is necessary to find an effective way to treat wastewater contaminated with it. In this study, Ni/Fe bimetallic nanoparticles were immobilized on reduced graphene oxide (NF@rGO), and used to dechlorinate CT in aqueous solution. Scanning electron microscopy (SEM) demonstrated that the two-dimensional structure of rGO could disperse nanoparticles commendably. The results of batch experiments showed that the 4N4F@rGO (Fe/GO = 4 wt./wt., and Ni/Fe = 4 wt.%) could reach a higher reduction capacity (143.2 mgCT/gcatalyst) compared with Ni/Fe bimetallic nanoparticles (91.7 mgCT/gcatalyst) and Fe0 nanoparticles (49.8 mgCT/gcatalyst) respectively. That benefited from the nickel metal as a co-catalyst, which could reduce the reaction activation energy of 6.59 kJ/mol, and rGO as an electrical conductivity supporting material could further reduce the reaction activation energy of 4.73 kJ/mol as presented in the conceptual model. More complete dechlorination products were generated with the use of 4N4F@rGO. Based on the above results, the reductive pathway of CT and the catalytic reaction mechanism have been discussed.

Electrochemically capacitive deionization of copper (II) using 3D hierarchically reduced graphene oxide architectures

Herein, we have developed the simple and novel 3-dimensional reduced graphene oxide (3D rGO) with large specific surface and superior electrochemical performance for capacitive deionization (CDI) of Cu2+ ions. The graphene oxides, produced from graphite powder by the modified Hummers method at pH 5, can be directly reduced into 3D rGO structures through the hydrothermal process at 150 °C for 12 h. The SEM/TEM images clearly indicate that 10–50 μm rGO can constitute the ordered structures with continuously inter-connected in-plane nanopores and micropores in 3D architecture, which can not only increase the surface area to 662 m2 g−1 but also facilitate the rapid transport of electrons and electrolyte ions. The 3D rGO exhibits an excellent electrochemical performance and the specific capacitance of 3D rGO is 508F g−1 at a scan rate of 5 mV s−1. Moreover, the applicability of 3D rGO was examined by CDI for the removal of Cu2+ ions. The electrosorption capacity of 3D rGO toward Cu2+ adsorption is 18.1 mg g−1 at 1.0 V. In addition, the electrosorption of Cu2+ ion follows the pseudo-second-order kinetics. Results of this study clearly demonstrate the excellence of 3D rGO to serve as a superior electrode material for Cu2+ ions removal, which can open a new way to design 3D rGO based composites for a wide variety of applications including water purification, catalysis and energy conversion and storage.

The structure of thermally reduced graphene oxide

The paper focused on the description of the reduced graphene oxide (rGO) structure. This material is obtained from a multistage production process. Each of these stages has a large impact on its structure (the number and type of functional groups, number of defect or the size of the flakes), and this in turn affects its properties. We would like to visualize the reduced graphene oxide, both using a diagram showing the atomic structure, as well as by imaging using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the paper, the elementary composition of selected elements and data obtained from X-ray photoelectron spectroscopy technique (XPS) will be also presented. Full Text: PDF ReferencesX. Peng, Y. Wu, N. Chen, Z. Zhu, J. Liu, and H. Wang, "Facile and highly efficient preparation of semi-transparent, patterned and large-sized reduced graphene oxide films by electrochemical reduction on indium tin oxide glass surface", Thin Solid Films 692, 137626 (2019). CrossRef L. Guo, Y.-W. Hao, P.-L. Li, J.-F. Song, R.-Z. Yang, X.-Y. Fu, S.-Y. Xie, J. Zhao and Y.-L. Zhang, "Improved NO2 Gas Sensing Properties of Graphene Oxide Reduced by Two-beam-laser Interference", Sci. Rep. 8, 1 (2018). CrossRef Y. S. Milovanov, V.A. Skryshevsky, , O.M. Slobodian, , D.O. Pustovyi, X.Tang, J.-P. Raskin, and A.N. Nazarov, "Influence of Gas Adsorption on the Impedance of Graphene Oxide", 2019 IEEE 39th Int. Conf. Electron. Nanotechnology, ELNANO 2019 - Proc. 8783946, CrossRef M. Reddeppa, B.-G. Park, , M.-D. Kim, K.R. Peta, N.D. Chinh, D. Kim, S.-G. Kim, and G. Murali, "H2, H2S gas sensing properties of rGO/GaN nanorods at room temperature: Effect of UV illumination", Sensors Actuators B. Chem. 264, (2018). CrossRef W. L. Xu, C. Ding, , M.-S. Niu, X.-Y. Yang, F. Zheng, J. Xiao, M. Zheng and X.-T. Hao, "Reduced graphene oxide assisted charge separation and serving as transport pathways in planar perovskite photodetector", Org. Electron. 81, 105663 (2020). CrossRef K. Sarkar, M. Hossain, P. Devi, K. D. M. Rao, and P. Kumar, "Self‐Powered and Broadband Photodetectors with GaN: Layered rGO Hybrid Heterojunction", Adv. Mater. Interfaces, 6, 20 (2019). CrossRef S. Pei and H. M. Cheng, "The reduction of graphene oxide", Carbon, 50, 9 (2012). CrossRef R. Muzyka, S. Drewniak, T. Pustelny, M. Chrubasik, and G. Gryglewicz, "Characterization of Graphite Oxide and Reduced Graphene Oxide Obtained from Different Graphite Precursors and Oxidized by Different Methods Using Raman Spectroscopy", Materials 11, 7 (2018). CrossRef M.-H. Tran and H. K. Jeong, "Influence of the Grain Size of Precursor Graphite on the Synthesis of Graphite Oxide", New Phys. Sae Mulli, 63, 2 (2013). CrossRef M.-H. Tran, C.-S. Yang, S. Yang, I.-J. Kim, and H. K. Jeong, "Influence of graphite size on the synthesis and reduction of graphite oxides", Curr. Appl. Phys., 14, SUPPL. 1 (2014). CrossRef N. Sharma, Y. Jain, , M. Kumari, R. Gupta, S.K. Sharma, K. Sachdev, "Synthesis and Characterization of Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) for Gas Sensing Application", Macromol. Symp. 376, 1 (2017). CrossRef M. Wei, L. Qiao, , H. Zhang, S. Karakalos, K. Ma, Z. Fu, M.T. Swihart, G. Wu, "Engineering reduced graphene oxides with enhanced electrochemical properties through multiple-step reductions", Electrochim. Acta, 258 (2017). CrossRef S. Drewniak, M. Procek, R. Muzyka, T. Pustelny, "Comparison of Gas Sensing Properties of Reduced Graphene Oxide Obtained by Two Different Methods", Sensors, 20, 11 (2020). CrossRef L. Li, R.-D. Lv, S. -C. Liu, Z. D. Chen, J. Wang, Y.-G. Wang, W. Ren, "Using Reduced Graphene Oxide to Generate Q-Switched Pulses in Er-Doped Fiber Laser", Chinese Physics Letters, 35, 11 (2018) CrossRef

Facile fabrication of ZnO nanorods modified with RGO for enhanced photodecomposition of dyes

Reduced graphene oxide/zinc oxide-rods composites (RGO/ZnO) were prepared through simple hydrothermal treatment of graphene oxide /zinc peroxide (GO/ZnO2) microspheres. The results of TEM, SEM and XRD show that the rod-like structure ZnO were successfully transformed from ZnO2 microspheres after high temperature treatment and combine well with GO. The synthesized RGO/ZnO-rods composites showed better photocatalytic performance as compared to pure ZnO2, ZnO and GO/ZnO2 under UV and visible-light irradiation. The improved photocatalytic performance of RGO/ZnO-rods composites was attributed to the uniform structure and excellent electrical conductivity of RGO, which could reduce the combination rate of the photo electron-hole pairs. After 5 consecutive cycles of testing, the RGO/ZnO-rods composites still have excellent photocatalytic performance, which was found to depend on ZnO content and NaCl concentration but was not affected by pH. The result of ESR experiment confirmed that the superoxide radicals (O2−) and hydroxyl radicals (OH) play an important role in the decolorization process of MO. Additionally, the kinetic rate constant (K) and mechanism of RGO/ZnO-rods composites had also been studied.

Functionalized reduced graphene oxide with aptamer macroarray for cancer cell capture and fluorescence detection.

Anintegrated aptamer macroarray functionalized with reduced graphene oxide (rGO) to specifically capture and sensitively detect cancer cellsis reported. The capture for cancer cells is based on effective recognition of the modified rGO surface through theaptamer against epithelial cell adhesion molecule (EpCAM). The rough structure of rGO enhances morphologic interactions between rGO film interface and the cancer cells, while super-hydrophilicity of modified rGO hinders nonspecific cell capture. The synergistic interactions offer the aptamer macroarray high efficiency of cancer cell capture. By means of a turn-on fluorescence strategy based on the conformation change of theaptamer induced by the target recognition, the enriched cancer cells can be directly read out at excitation/emission wavelengths of 550/680nm without washing, separation, and dying steps. The working range is1 × 102 to 2 × 104 cells per mL with a detection limit of 22 cells per mL. The results indicate that the aptamer macroarray has a considerable foreground for early diagnosis, therapy, and monitoring of cancer. Graphical abstract.

Functional reduced graphene oxide/cobalt hydroxide composite for energy storage applications

Material storage property enrichment with good electrochemical performance is a foremost challenge. Cobalt hydroxide and reduced graphene oxide (rGO) composite synthesized via chemical precipitation method showed improved specific capacitance and cycle stability. The unique rGO layered structure in composite enhanced overall electrochemical performance. Raman spectra revealed disordered rGO structure and A1g mode of Co(OH)2 in composite. rGO/Co(OH)2 electrode showed increased specific capacitance of 1100 Fg−1 at 0.5 Ag−1 with better rate capability and good stability (98.1%) after 2000 cycles. These results proved that rGO/Co(OH)2 is a perfect electrode for electrochemical energy storage applications.

Rational design of cathode structure based on free-standing S/rGO/CNT nanocomposite for Li-S batteries

Sulfur / reduced graphene oxide / carbon nanotube (S/rGO/CNT) composite cathodes were fabricated as laminar-structured free-standing papers to develop high-capacity lithium sulfur batteries (Li-S). Here, the rGO content improved the electronic conductivity and acted as a buffer to accommodate volumetric expansion of sulfur together with CNTs. In this study, it was aimed to benefit from the synergistic effect of the hybrid structure of rGO and CNT, and to determine the effect of rGO and CNT ratio on the S/rGO/CNT cathode capacity. For this purpose, the free-standing, flexible and binder-less paper cathodes were rationally designed by using different rGO/CNT ratios via a vacuum filtration method. To characterize the fabricated S/rGO/CNT cathodes, thermogravimetric analysis (TGA), field emission gun scanning electron microscopy (FEG-SEM), energy dispersive x-ray spectrometer (EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and electrochemical performance tests were used. In the fabrication of S/rGO/CNT cathodes, the obtained results showed that the use of 2:1 rGO/CNT ratio exhibited more mesoporous, well-designed laminar structure and higher discharge capacity according to 1:1 and 1:2 rGO/CNT ratios. As a result, the most effective cathode was achieved at 0.1C after 300 cycles, exhibiting a 701 mA h g−1 discharge capacity. According to the obtained results, the fabricated cathode structures could be promise as novel high-performance Li-S cathode materials with a facile method.

Visible light photoactivity of 2D nanocomposites of CdS-TiO2 and CdS-TiO2-rGO

Abstract The CdS-TiO2-rGO composites of various molar ratios were prepared through a modified solvothermal/hydrothermal process. X-ray diffraction and scanning electron microscope were used for the morphological and structural characterization of the material. The sheet like morphology of the titania and CdS were clearly evident from the scanning electron microscope image of the samples. The composite 2CdS:1TiO2:rGO(1%) shows highest activity with rate constant 0.00258 min−1. Ultrathin two dimensional sheets-like structure, electrostatic interaction, and presence of rGO (reduced graphene oxide) as supporting matrix are attributed to the highest photocatalytic performance of this composite.

Fabrication of Erythrina senegalensis leaf extract mediated reduced graphene oxide for cardiac repair applications in the nursing care

The present work discloses the use of Erythrina senegalensis leaf extract for reduction of graphene oxide (GO) via a simple one pot technique by avoiding the use of toxic reducing agents. The effective reduction of GO and consequent capping by oxidized plant polyphenols were demonstrated by different spectroscopic and microscopic studies. Fourier-transform infrared (FTIR) spectroscopy indicated the stabilization of RGO with oxidized polyphenols of plant extract. Transmission electron microscopy (TEM) images confirmed the thin, transparent, silk sheet like structure of RGO. Further, the produced RGO displayed a concentration-dependent toxicity toward cardiac cell lines of Catla catla (SICH). In addition, the present study provided the green fabrication of RGO for the development of new products based on graphene for cardiac tissue engineering applications in nursing care.

Study of Optical and Electrical Properties of Graphene Oxide

Present work reports the Graphene oxide (GO) optical and electrical properties and its variation after graphene oxide reduction. Modified Hummers’ method route is adopted for synthesis of present graphene oxide (GO) material. Graphene oxide (GO) was reduced by voltage application in the GO solution. In voltage application process the Cu electrode was dipped in the GO solution with biasing of 10 V for 2 h. The thin films of two materials graphene oxide (GO) and reduced graphene oxide (rGO) are deposited in square shape using Masking tape by spin coating technique. The materials were characterized by X-Ray Diffraction (XRD), Scanning electron microscopy (SEM) Raman spectroscopy and UV–Vis spectroscopy. The XRD peak of GO raised at 10.4° and rGO at 25.9°. The SEM images show the sheet structure of GO and rGO. The Raman peak of GO and rGO show G peak at 1597 cm−1, 1608 cm−1 and D peak at 1353 cm−1, 1347 cm−1 respectively. The ID/IG ratio of GO and rGO is 0.89 and 0.96, respectively. The peak of GO and rGO UV–Vis absorbances is 230 nm and 270 nm, transmittance is 85% and 75%. respectively. The tauc plot gave the bandgap value of GO is 3.84 eV and rGO is 2.87 eV. The measurement of sheet resistance using desktop bench multimeter of GO is 2MΩ/sq. and rGO is 1.5kΩ/sq. The calculation of Hacce figure of merit for rGO as transparent electrode gives the value 3.75 × 10−5 Ω−1.