Graphite Peak Research Articles

Characterization and Thermal Treatment of the Black Mass from Spent Lithium-Ion Batteries

Recycling lithium-ion batteries is crucial for the environment and the sustainability of primary resources. In this paper, we report on the characterization of two grades of black mass from spent lithium-ion batteries (with typical lithium–nickel–manganese–cobalt oxide cathode compositions) and their behavior during heating trials. This study paves the way for optimizing lithium-ion battery recycling processes by fully characterizing black mass samples before and after heating. A gas release under pyrolytic conditions was detected using a multicomponent mass spectrometer and included dimethyl carbonate, diethyl carbonate, oxygenated hydrocarbons, hydrocarbons, and other miscellaneous gases. This can be attributed to the evaporation of volatile organic compounds, conductive salt, organic polyvinylidene fluoride binder, and an organic separator such as polypropylene. Thermal treatment led to the partial decomposition of the binder into char and newly formed fluorine cuboids. The compaction of the cathode decreased, but the remaining binder limited recycling processes. By heating the black mass samples to 900 °C, the intensity of the X-ray diffraction graphitic carbon peak decreased, and the lithium metal oxides were reduced to their corresponding metals. The graphite in the black mass samples was structurally more disordered than natural graphite but became more ordered when heated.

C K-XANES of graphitic carbons with oxygenated functional groups.

The X-ray absorption near-edge structure (XANES) in the C K region of graphite oxide (GO) exhibits a complicated and broad profile in the π* (285eV)-σ* (293eV) region due to oxygenated carbon atoms. To clarify the oxidation effect on carbon atoms in the spectral profile of GO, we measured the C K-XANES of various oxygenated aromatic compounds and theoretically analyzed them using density function theory (DFT) calculations. From the measured and calculated C K-XANES, the π* peaks of oxygenated carbon atoms shift to the higher-energy range by 0.5-4eV from 285.5eV of the typical π* peak of graphite. The energy positions of the shifted π* peaks depend on both the oxygenated functional groups and the molecular structures, confirming that the energy shifts of the π* peaks due to oxygenated carbon atoms cause the broad and complicated peak profiles in the π*-σ* region in C K-XANES of GO.

Synthesis of Reduced Graphene Oxide by Ethyl Acetate and Its Utilization in Determining Hydroxychloroquine in Wastewater and Pharmaceutical Samples

AbstractAn easy and sensitive sensor made by carbon paste modified with reduced graphene oxide rGO‐CPE was developed for the detection of hydroxychloroquine (HCQ). Graphene oxide GO was reduced using ethyl acetate. Scanning electron microscope and X‐ray diffraction (XRD) were used for the characterization of rGO powder. The reduction of graphene oxide was confirmed by the disappearance of the identical peak of graphite in the XRD pattern. Herein, the modified electrode rGO‐CPE showed stronger electrochemical activity compared to bare CPE. The electrochemical behavior of HCQ was studied by cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. The mechanism of the HCQ oxidation in the surface of rGO‐CPE was found to be controlled by an adsorption process with the transfer of 2 electrons. Furthermore, the standard heterogeneous rate constant (Ks) and the surface concentration of electroactive species (Γ) were calculated and the obtained values are 1.03×10−2 cm s−1 and 1.07×10−10 mol cm−2, respectively. Differential pulse voltammetry was used for HCQ quantification as a result a linear relationship between HCQ concentration and the oxidation peak current was obtained in the range from 1.0×10−7 to 8.0×10−6 mol L−1 and from 8.0×10−6 to 1.0×10−4 mol L−1, with a detection limit (LOD) of 6.29×10−8 mol L−1 and a sensitivity of 6.42 A L mol−1 cm−2. Moreover, the rGO‐CPE was successfully applied for the detection of HCQ in wastewater and pharmaceutical samples.

Ultrsonication mediated Iron-doped reduced graphene oxide nano-sheets exhibiting unique physico-chemical properties and biomedical applications

In this study, reduced graphene oxide nanosheets have been synthesised using hummers method in the laboratory conditions. Lateral thickness came to be ∼8–10 nm thickness profile. Crystallographical properties of the reduced graphene oxide sheets were achieved from the different X-Ray Diffraction (XRD) studies, thereby achieving (002) for reduced graphene oxide, when compared to (001) (hkl) planes for intermediate Graphitic peak, respectively. The as-formed diffraction planes signifies the formation of diffraction planes at ∼25° diffraction angle for effective formation of Reduced graphene oxide, resulted from the reduction and exfoliation from pure Graphitic structure. The nano-composites of the as-prepared Fe-Doped Reduced graphene oxide sheets has been analysed, employing the Fourier-Transform Infra-Red (FT-IR) spectroscopy approach. The elucidation of the different molecular vibrational aspects of the transitional d-block metal Fe doped Reduced graphene oxide sheets have been studied for the justification of Fe-incorporated Reduced graphene oxide sheets. Further, the micrographical analyses of the Fe-Doped different layered RGO sheets has been evaluated by High-Resolution Transmission Electron Microscopy (HR-TEM) with their respective EDAX analyses exhibting an average diameter of the as-formed composites ∼26.78 nm. Finally, the biophysical aspects of the as-prepared nano-composites were explored into the prokaryotic model organism of Gram –ve (Escherichia coli) and Gram + ve (Staphylococcus aureus) bacterium species. It is perceived that, uncovering and evaluating the underlying interaction(s) taking place between the magnetic based materials at the nano-scale posessing magnetically transistional metallic attributes within the biological organisms, would help to pave the way in unveiling the quantum-mechanical and thermodynamical attributes taking place at the nano-scale rate and kinetics of the material-bio interface.

Lattice Distortion, Amorphization and Wear Resistance of Carbon-Doped SUS304 by Laser Ablation.

Lattice distortion and amorphization of carbon-doped SUS304 by variation of the laser output were investigated in terms of phase formation and the bonding state. The laser output was changed by 10% in the range of 60% to 100% after covering the SUS304 with carbon paste. A graphite peak and expanded austenite (S-phase) peak were observed in the carbon-doped SUS304, and Rietveld refinement was performed to identify the lattice distortion. The lattice constant of SUS304 was initially 3.612 Å, but expansion lattice distortion occurred in the carbon-doped SUS304 as a result of the S phase formation and carbon doping, and the lattice constant increased to 3.964 Å (100% laser output). X-ray photoelectron spectroscopy analysis for the bonding state of the carbon-doped SUS304 showed that the sp2/sp3 ratio decreased from 3.21 (70% laser output) to 2.52 (100% laser output). The residual stress in the lattice was accumulated due to carbon doping by high thermal energy, which resulted in the formation of amorphous carbon. The bonding environment was represented by the ID/IG ratio using Raman analysis, and it increased from 0.55 (70% laser output) to 1.68 (100% laser output). During microstructure analysis of the carbon-doped SUS304, disordered structures by amorphization were observed in the carbon-doped SUS304 by the greater than 90% laser output. The amorphous carbon filled the lattice grains or voids to lubricate the surface, which improved the friction coefficient and wear rate from 0.23 and 7.63 mm3(Nm)−110−6 to 0.09 and 1.43 mm3(Nm)−110−6, respectively.

Cosolvent Engineered Phosphaphenanthrene-Based Self-Extinguishing Electrolyte for Safer Lithium-Ion Batteries

Battery-induced fire accidents are on the rise worldwide. The severity of battery fires has a significant correlation with the combustion characteristics of carbonate electrolytes, which is the main fuel of a battery. Here, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), an environmentally benign, smokeless, and highly efficient flame retardant, is introduced into a carbonate electrolyte for the first time to formulate a self-extinguishing electrolyte. It is shown that 5 wt % DOPO in the carbonate electrolyte is enough to achieve flame retardancy. Moreover, in the thermal runaway test, adding DOPO effectively delays the exothermic peak of graphite (Gr) and reduces the amount of heat. The cosolvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (TTE) may act as a solvent shell to weaken the irreversible decomposition of DOPO on Gr at low potentials and improve the interface compatibility, enabling acceptable cycling performance of LiFePO4 (LFP)–Li batteries with a 99.7% capacity retention after 65 cycles. The design strategy for electrolyte formulation provides a promising path to revisit obsolete flame retardants of the past, which gives insights into the development of nonflammable electrolytes.

Low-temperature synthesis of graphite flakes and carbon-based nanomaterials from banana peels using hydrothermal process for photoelectrochemical water-splitting

Herein, we report the synthesis of carbon nanostructures from banana peels at low hydrothermal temperatures. A one-step hydrothermal method was used, and the desired product was obtained at 220 °C using two dispersant solvents (distilled water (S1) and ethanol (S2)). The formation of carbon nanomaterials and graphite flakes has been confirmed through various characterization techniques. The Scanning Electron Microscopy (SEM) analysis shows a graphite flake-like morphology using water as a solvent and a mix-up of graphite flakes and carbon nanoparticles presence using ethanol as a solvent. Two primary elements i-e., carbon (C) and oxygen (O) were observed in the Energy Dispersive X-ray (EDX) analysis. The X-ray Diffraction (XRD) analysis shows the graphitic diffraction peak that confirms the formation of graphite flakes and carbon nanomaterials with good crystallinity . Fourier Transform Infrared (FTIR) analysis reveals the signature of O–H, C–H, C–O, C–O 2 , bonds along with C O and C C bonds. UV–Visible (UV–Vis) spectroscopy shows absorption at 230 nm for (S2) and 270 nm for (S1) which correspond to the π-π* and n-π* transitions of C C and C O, respectively. The photoelectrochemical (PEC) analysis shows that the sample (S2) has a higher photocurrent density and low charge-transfer-resistance than the sample (S1) because of its finer size. The study thus provides a simple pathway for the preparation of carbon-based nanomaterials on a large scale. • Graphite flakes and carbon-based nanostructures were prepared through a one-step hydrothermal route from banana peels. • Two dispersant solvents i-e, ethanol and water were used as a media in the reaction procedure. • SEM reveals graphite flakes and nanoparticle shape morphology while XRD shows the graphitic peak (002) with good crystallinity. • FTIR shows the signature of C–H, C–O, C–O 2 bonds along with C O and C C bonds. • Photoelectrochemical analysis shows higher photocurrent density and flat-band potential, and low charge-transfer-resistance for the sample prepared in ethanol.

Low-Temperature Ethanol Sensor via Defective Multiwalled Carbon Nanotubes.

This paper focuses on the fabrication of defective-induced nanotubes via the catalytic chemical vapor deposition method and the investigation of their properties toward gas sensing. We have developed defective multi-walled carbon nanotubes with porous and crystalline structures. The catalyst layer used in CNTs’ growth here was based on 18 and 24 nm of Ni, and 5 nm of Cr deposited by the dc-sputtering technique. The CNTs’ defects were characterized by observing the low graphite peak (G-band) and higher defect peaks (D-band) in the Raman spectrum. The defectives sites are the main source of the sensitivity of materials toward different gases. Thus, the current product was used for sensing devices. The device was subjected to various gases such as NO, NO2, CO, acetone, and ethanol at a low operating temperature of 30 °C and a concentration of 50 ppm. The sensor was observed to be less sensitive to most gas while showing the highest response towards ethanol gas. The sensor showed the highest response of 8.8% toward ethanol at 30 °C of 50 ppm, and a low response of 2.8% at 5 ppm, which was investigated here. The signal repeatability of the present sensor showed its capability to detect ethanol at much lower concentrations and at very low operating temperatures, resulting in reliability and saving power consumption. The gas sensing mechanism of direct interaction between the gas molecules and nanotube surface was considered the main. We have also proposed a sensing mechanism based on Coulomb dipole interaction for the physical adsorption of gas molecules on the surface.

Structural Restoration of Degraded LiFePO 4 Cathode with Enhanced Kinetics Using Residual Lithium in Spent Graphite Anodes

Structural Restoration of Degraded LiFePO ₄ Cathode with Enhanced Kinetics Using Residual Lithium in Spent Graphite Anodes

Hydrogen production via photoreforming of wastewater under LED light–driven over CuO@exfoliated g–C3N4 nanoheterojunction

As the global interest heading towards net zero emission by 2050, clean hydrogen production technologies becomes limelight among the research community. Besides, the generation of large quantity of industrial wastewaters creates huge dilemma and needs special attention. In this work, synthetic wastewater using formaldehyde (FA) as a model organic pollutant was utilized to produce hydrogen. The photocatalyst, CuO@exfoliated g–C3N4 nanoheterojunction was synthesized by an acid treatment and facile chemical precipitation technique. XRD results confirmed the successful formation of exfoliated g–C3N4 by expanding the interlayer spacing of the nanosheets via shifting of characteristic peak of graphite towards lower 2θ from 27.97° to 27.04°. Meanwhile, the BET surface area of CuO@exfoliated g–C3N4 (199.3 m2/g) was remarkably enhanced as compared to bulk g–C3N4 (34.5 m2/g) and exfoliated g–C3N4 (104.4 m2/g). The existence of large pores (3.55 cm3/g) in CuO@exfoliated g–C3N4 promotes the accessibility of reactant to the surface active sites, escalating the redox reactions. Study on hydrogen production via photoreforming of aqueous formaldehyde over the prepared photocatalysts were conducted. Interestingly, hydrogen generated using CuO@exfoliated g–C3N4 (3867 μmol/g) was greatly enhanced by 7 times and 13 times than the counterparts catalysts, exfoliated g–C3N4 (532 μmol/g) and pure CuO (271 μmol/g) respectively. By employing the CuO@exfoliated g–C3N4 nanoheterojunction, the optimum hydrogen with apparent quantum efficiency (AQE) of 5664 μmol/g and 22% were obtained respectively. Besides, S–scheme reaction mechanism was proposed based on heterojunction formed between the p–type CuO and n–type exfoliated g–C3N4 nanosheets.

Effect of ball milling speed on the quality of Al2O3 stripped graphene in a wet milling medium

Graphene nanosheets (GNSs)/Al2O3 composites were synthesized by wet milling. In this study, the effects of wet milling speed on the layer distribution, quality and conversion efficiency of graphene in GNSs/Al2O3 composites were studied using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), raman spectroscopy, fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results show that the intensity of graphite peak decreases and the conversion efficiency of graphene increases with the increase of rotational speed in the range of 200–300 rpm, and a small amount of graphene coated Al2O3 nanoparticles were found in GNSs/Al2O3 composites. The number of layers (≤10 layers) of GNSs gradually increases with the increase of ball milling speed. When the rotational speed is 300 rpm, the graphene conversion efficiency is the highest. At different rotational speeds, graphene defects were the least influential marginal defects. There was no characteristic peak of graphene oxide (GO) appeared in the composite, indicating a small oxidation degree of graphene.

Enhanced mechanical properties and electrical conductivity of Chitosan/Polyvinyl Alcohol electrospun nanofibers by incorporation of graphene nanoplatelets

The subject of this paper is to develop a highly conductive Graphene nanoplatelets (GNPs)-Chitosan (CS)/Polyvinyl Alcohol (PVA) (GNPs-CP) nanofibers with excellent mechanical properties. An experimental study was designed to produce nanofibers based on CP nanofibers as matrix and GNPs as reinforcement materials. The microstructure and the surface morphology of the electrospun nanofibers along with their electrical and mechanical properties were examined to study the effect of GNPs content. The SEM results showed that the gradual increase in GNPs content led to a porous web like morphology with no bead. There is a decrease in the diameter of nanofibers by increasing the concentration of GNPs to 1 wt% GNPs from 370 ± 40 nm for CP blend to 144 ± 18 nm for 1 wt% GNPs. Transmission electron microscopy results depicted that GNPs were dispersed uniformly confirmed by the absence of characteristic peak of graphite at 2θ = 26.5°. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy results indicate the occurrence of a few interactions between GNPs and CP matrix. Nitrogen adsorption/desorption measurement demonstrated that increasing GNPs content increased the specific surface area of nanofibers from 238.377 to 386.708 m2/g for 0 and 1 wt% GNPs content. The test results also show that the presence of GNPs considerably enhances tensile strength, elastic modulus and electrical conductivity. Furthermore, the toughness of GNPs-CP nanofibers including 1 wt% GNPs significantly improved (12-fold) compared to the one for CP nanofibers. So, the proposed composite provides a decent functionality for nanofibers as scaffolds in tissue engineering applications.

Microstructural Analysis of Novel Preceramic Paper-Derived SiCf/SiC Composites.

This paper presents the results of microstructural analysis of novel preceramic paper-derived SiCf/SiC composites fabricated by spark plasma sintering. The sintering temperature and pressure were 2100/2200 °C and 60/100 MPa, respectively. The content of fibers in the composites was approx. 10 wt %. The SiCf/SiC composites were analyzed by positron annihilation methods, X-ray diffraction technology, scanning electron microscopy, and Raman spectroscopy. Longer sintering time causes the proportion of the 6H-SiC composition to increase to ~80%. The increase in sintering temperature from 2100 °C to 2200 °C leads to partial transition of 4H-SiC to 6H-SiC during the sintering process, and the long-life component of positrons indicates the formation of Si vacancies. The Raman characteristic peaks of turbostratic graphite appear in the Raman spectrum of SiC fibers, this is caused by the diffusion of carbon from the surface of the SiC fiber and the preceramic paper during the high-temperature sintering process.

The Different Inclusions’ Characteristics between Natural and Heat-Treated Tanzanite: Evidence from Raman Spectroscopy

In this paper, Raman spectroscopy experiments were used to distinguish the characteristics of inclusions (calcite, anatase, graphite etc.) between natural and heat-treated tanzanite. These characteristics were preliminarily divided according to their pleochroism. In natural unheated tanzanite (N5), calcite inclusion is often interspersed with dolomite and has Raman shifts around 156, 283, 710, and 1087 cm−1. In other high temperature treatment samples, the baseline of calcite increased and their Raman peaks gradually shifted towards lower frequencies. Anatase inclusions in natural tanzanite (N5) have four characteristic Raman peaks around 146, 394, 514, and 641 cm−1. Because of the longer Ti-O bond and the wider bond angle distribution caused by high temperature, fewer Raman peaks were observed and the peaks’ intensities were weakened in the heat-treated T7 sample. The black graphite inclusions are often scattered or have a dotted distribution. The most obvious difference between natural and heat-treated samples is that the latter lack the characteristic 1350 cm−1 Raman peak of graphite, thus representing the order and structural incompleteness of graphite. In addition, there are other inclusions in natural unheated tanzanite, such as lead-grey molybdenite with strong metallic luster, randomly scattered prehnite with white dots, orange-yellow rounded rutile, and metallic luster hematite.

A correlation of surface/textural properties of carbon derived from Musa acuminata stem and its high supercapacitance performance with superior cycle stability

Carbonization of variety of biomass materials and activation using metal salts, oxides carbonates etc., aids in increasing its specific surface area (SSA) and activation site density utilized in many applications. Here, Musa acuminata (banana) stem has been carbonized at 450 °C and activated using five different porogens like KOH (C-1), ZnCl2 (C-2), KCl (C-3), NaHCO3 (C-4) & K2HPO4 (C-5) at 750 °C. The physico-chemical properties of these carbon materials have been analysed using P-XRD, SEM, EDS, TEM, SAED, BET and Raman techniques. Apart from usual amorphous graphitic peak in carbon materials, inorganic metal oxides/carbonate/silicate peaks are present due to interaction among biomass derived elements like C, O, K, Mg, Si & P etc., at high temperatures. Among ACs, C-1 shows superior surface properties with very high SSA of 3351 m2 g−1 but gave only specific capacitance (Cs) of 75 F g−1 at 5 A g−1. But C-3 with moderate surface properties exhibited a high Cs of 339 F g−1 at 5 A g−1. C-3 was subjected to continuous charge-discharge cycles at 15 A g−1 indicated 80% Cs retention & 100% coulombic efficiency at 25,000th cycle. A symmetric coin cell (CR2032) fabricated using C-3 in 1 M KOH solution, exhibited a high Cs, specific energy (SE) & specific power (SP) of 88 F g−1 at 2 mV s−1, 62 F g−1 at 1 A g−1 remarkably 34.4 Wh kg−1 and 25.6 kW kg−1 respectively. The coin cell was subjected to enormous number (75,000) of cycles at 25 A g−1 showed Cs retention of 75% with 100% coulombic efficiency. Two-coin cells, each cell operating in the potential range from 0–2 V connected in series are used to power 1-watt LED for 3 minutes.

Partial black porcelain using wood charcoal as carbon source: Characterization of porcelain body part

This paper observes the fabrication of partial black porcelain by carbon diffusion from wood charcoal as a solid carbon source, and the characterization of body at bottom area. The porcelain cup was created by conventional ceramic technique. For second firing step, the cup was set on the wood charcoal pieces contained in a closed refractory container and fired at 1250 °C for 1 h. The traces of carbon compounds at different positions on a cross-section sample were detected by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Graphitic carbon and Si − O − C were discovered. Furthermore, graphite peak was detected by X-ray diffraction (XRD). This work provides a confirmation of solid diffused carbon from wood charcoal into the porcelain body by scientific techniques.

Synthesis and Characterization of Supercapacitor Materials from Soy

Renewable resources and their byproducts are becoming of growing interest for alternative energy. Here, we have demonstrated the use of Arkansas’ most important crop, soy, as a carbon precursor for the synthesis of carbonized activated materials for supercapacitor applications. Different soy products (soymeal, defatted soymeal, soy flour and soy protein isolate) were converted into carbonized carbon and co-doped with phosphorus and nitrogen simultaneously, using a facile and time-effective microwave synthesis method. Ammonium polyphosphate was used as a doping agent which also absorbs microwave radiation. The surface morphology of the resulting carbonized materials was characterized in detail using scanning electron microscopy. X-ray photoelectron spectroscopy was also performed, which revealed the presence of a heteroelemental composition, along with different functional groups at the surface of the carbonized materials. Raman spectroscopy results depicted the presence of both a graphitic and defect carbon peak, with defect ratios of over one. The electrochemical performance of the materials was recorded using cyclic voltammetry in various electrolytes including acids, bases and salts. Among all the other materials, soymeal exhibited the highest specific capacitance value of 127 F/g in acidic electrolytes. These economic materials can be further tuned by changing the doping elements and their mole ratios to attain exceptional surface characteristics with improved specific capacitance values, in order to boost the economy of Arkansas, USA.

Investigation on abrasive wear mechanism of single diamond grain in flexible scribing titanium alloy

Abrasive belt grinding technique has been gradually used in precision machining those attractive materials of aerospace field. The excellent performance of rigid-flexible composited diamond belt shows great application prospect while its abrasive wear mechanism is deeply revealed. Therefore, a series of theoretical and experimental studies are performed to explore the wear mechanism of single diamond grain in flexible scribing titanium alloy in this work. Three-dimensional finite element simulation model was built to investigate the elastic frictional wear process between a diamond grain and the titanium alloy sample under different combinations of processing parameters. The simulation results showed that the normal force and grain size contributed much to frictional stress and the friction speed had the greatest effect on the frictional temperature. On this basis, the flexible scribing experiments of titanium alloy sample by using single diamond grain were conducted to verify the effect of scribing parameters on diamond grain wear. Raman scattering analysis, chemical thermodynamic calculation and X-ray photoelectron spectroscopy analysis methods were proposed to further research the essential wear of diamond grain at elevated temperature. The results indicated that the physical wear caused by higher scribing force was the main pattern at lower temperature. When the temperature reached up to 1100 K, Raman shifts peak of graphite corresponding to 1544 cm−1 was detected to illustrate the graphite transformation of diamond crystal structure, and the existence of TiO2 and CO bond were confirmed to explain the oxidation wear of diamond grain at the atmosphere of air medium. This research work provides an important theoretical basis for restraining the diamond belt wear in precision grinding operation of titanium alloys.

Boosting the Rate Performance of Li–S Batteries via Highly Dispersed Cobalt Nanoparticles Embedded into Nitrogen-Doped Hierarchical Porous Carbon

Boosting the Rate Performance of Li–S Batteries via Highly Dispersed Cobalt Nanoparticles Embedded into Nitrogen-Doped Hierarchical Porous Carbon

Surface Enhanced Raman Scattering in Graphene Quantum Dots Grown via Electrochemical Process.

Graphene Quantum dots (GQDs) are used as a surface-enhanced Raman substrate for detecting target molecules with large specific surface areas and more accessible edges to enhance the signal of target molecules. The electrochemical process is used to synthesize GQDs in the solution-based process from which the SERS signals were obtained from GQDs Raman spectra. In this work, GQDs were grown via the electrochemical process with citric acid and potassium chloride (KCl) electrolyte solution to obtain GQDs in a colloidal solution-based format. Then, GQDs were characterized by transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy, respectively. From the results, SERS signals had observed via GQDs spectra through the Raman spectra at D (1326 cm−1) and G (1584 cm−1), in which D intensity is defined as the presence of defects on GQDs and G is the sp2 orbital of carbon signal. The increasing concentration of KCl in the electrolyte solution for 0.15M to 0.60M demonstrated the increment of Raman intensity at the D peak of GQDs up to 100 over the D peak of graphite. This result reveals the potential feasibility of GQDs as SERS applications compared to graphite signals.