Graphite Content Research Articles

Graphite Content Identification with Laboratory and Field Spectral Induced Polarization Measurements

Graphite, a critical raw material, prompts interest in assessing former quarries for volumetric content, driving the need for accurate prospection techniques. We explore the efficacy of spectral induced polarization (SIP) imaging at field scale for this purpose. Field measurements in a quarry with unknown graphite content underscore the need for assessment before drilling due to abrupt topography. Due to the lack of ground truth required to calibrate existing petrophysical models, we propose using SIP laboratory measurements to achieve the quantitative interpretation of the imaging results. We conducted experiments at two scales: rock plugs for material response and ground rocks of varying sizes for textural analysis. The rock plugs allow us to investigate the response of the material, while the ground samples permit us to understand changes in the SIP response for varying textural properties. Our lab work establishes power-law relationships between polarization (expressed in terms of normalized chargeability) and graphite content, as well as relaxation time and grain size. Salinity dependence is noted between chargeability, normalized chargeability, and relaxation time. Utilizing these findings, we provide a quantitative interpretation of field SIP imaging results.

Rice Straw‐Derived Biochar as Anode Material for Lithium‐Ion Battery: A Step toward Sustainable Development

In the present study, sustainable upscaling of rice straw, an agri‐residue, is explored as the way to obtain active material to prepare anode for use in lithium‐ion batteries (LIBs). The biochar having high carbon and low silica content is prepared by initial chemical treatment of rice straw followed by its pyrolysis. The pristine and modified biochar are characterized using Brunauer‐Emmett‐Teller surface area, energy dispersive X‐ray spectroscopy, carbon hydrogen nitrogen sulphur elemental analysis, scanning electron microscopy, X‐Ray power diffraction, Fourier transform infrared spectroscopy and Raman analysis and the modified biochar show an enhancement in graphitic carbon content. A coin cell is assembled using anode prepared from modified biochar. The coin cell is subjected to electrochemical testing and had a discharge capacity of 352 mA.h g−1. Further, the coin cell is tested for 100 cycles and a columbic efficiency of 99.7% was obtained. Therefore, biochar derived from pyrolysis of rice straw has the potential to be used as anode material for LIBs.

Electrical sliding friction wear behaviors and mechanisms of Cu–Sn matrix composites containing MoS2/graphite

Cu–Sn matrix composites were prepared by vacuum hot press sintering technique with the addition of MoS2, graphite and a mixture of MoS2/graphite, respectively. The friction wear behaviors and contact resistance of the three composites under different currents were investigated and compared. The friction film formed on the friction surface was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The wear mechanism and the evolution of friction film composition of the composites under different currents were revealed. The results showed that MoS2 and graphite had synergistic lubrication effects. The Cu–Sn-Graphite-MoS2 composite exhibited low wear rates and the lowest and most stable contact resistance. MoS2 could effectively promote the formation and integrity of the friction film and optimize the friction wear performance. With the increase of current, the graphite content in the friction film rose, which helped to reduce the oxidation and consumption of the friction film. The increase in current accelerated the shedding of lubricating particles and the softening of lubricating film, making the lubricating film denser and reducing the oxidation depth.

Water-based and tannin-assisted liquid-phase exfoliation for a sustainable production of graphene

Graphene is a material with high potential in the development of advanced applications, such as 3D printing. In the current scenario, it is obvious that technological progress should align with sustainability, therefore, it is necessary to search for efficient and sustainable alternatives to the liquid phase exfoliation of graphene. In this work, chestnut tannins were employed as surfactants for graphene exfoliation in aqueous media, via ultrasound exfoliation and high-shear exfoliation. The effect of the initial concentration of graphite, the initial concentration of tannin and the exfoliation time over the concentration of the obtained graphene suspensions and mass yield was assessed, showing that comparable values to NMP based exfoliation were obtained. Obtained graphene flakes were morphologically characterized by Raman spectroscopy and Transmission Electron Microscopy, and results showed that high-shear exfoliation resulted in graphene flakes with the highest ID/IG ratio and more homogenous thickness. Life Cycle Assessment of the exfoliation processes revealed the environmental benefits of water-based exfoliation processes compared to traditional process based on NMP solvent. A sensitivity analysis showed that environmental impacts could be reduced if renewable energy sources are considered. High-shear exfoliation with initial concentration of graphite of 5 mg·mL−1, tannin concentration of 1 mg·mL−1 and shearing time of 15 min emerged as the most balanced choice between quality and sustainability.

Experimental Investigation and Analysis of Mechanical Properties of Chopped Strand Mat-E Glass Fiber Polyster Resin & Graphite Powder Composites

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. In view of this the mechanical performance of the composite material is essential. The objective of the present work is to analyze the effect of graphite powders content on the mechanical behavior of woolen E-glass 350gm-Glass fiber reinforced. Five different types of composites are fabricated using 0%,2%,4%,6%,8%wt of graphite powders with woolen-E glass fiber and polyester resin. The polyester resin, catalyst and accelerator are mixed in 50:1:1weight ratio in polyester matrix graphite. The aim of the project is to investigate the effect of graphite powders with woolen e-glass 350gm for making the composite material stronger and tougher. The investigation is carried out by mixing different weight percentages of the graphite powders with the polyester resin and preparing individual samples. After woolen- eglass preparation, the materials were properly mixed using the hand-lay techniques and different specimens were prepared with different compositions of the graphite powders. After all the samples were prepared, mechanical tests were carried out on the samples to ascertain the changesobserved due to the composition of graphite powders. The obtained results of various samples specimens were compared and graphically charted to characterize the new composites material. Keywords: MattE-Glass 350gm; Polyester resin; Graphite powders; Hand- Lay technique ; Catalyst & Accelerator.

Influence of copper salts on the physical and mechanical properties of copper–graphite composite materials

We investigated composite materials based on electrolytic copper powder containing 1 and 5 wt. % powder of colloidal graphite the addition of trace amounts of copper sulfate and acetate. The materials were obtained through double cold pressing in a mold at a pressure of 600 MPa, intermediate sintering (annealing) in hydrogen at a temperature of 870 °C, and final sintering in vacuum at the copper premelting temperature. To analyze the influence of copper salts on the density, porosity, electrical resistivity, and strength of copper–graphite composite materials, we employed X-ray phase analysis, scanning electron microscopy, conducted strength tests in three-point bending, and determined electrical resistivity. We established that higher graphite content results in increased porosity and electrical resistivity of composite materials, along with decreased strength. In the materials containing copper sulfate, copper is reduced from the salt in the form of nanodispersed particles on the surfaces and inside graphite flakes, leading to a decrease in electrical resistivity compared to copper–graphite composites without salt additives. When copper acetate was added to the composite material, copper is reduced from the salt mainly on the surfaces of graphite particles in the form of microdispersed particles and their aggregations, as the copper acetate solution does not wet the graphite. In this case, the electrical resistivity was somewhat higher than that of the composite with sulfate but lower than that of the material without salts. The bending strength of the studied materials decreased as salts were introduced due to increased porosity and emerging defects in the crystal structure of graphite during its intercalation with copper.

Densification and corrosion properties of graphite reinforced binderless TiC70N30 ceramic composites

In this study, binderless TiC70N30 ceramic composites with varying graphite (TiC70N30–Gr) reinforcements were fabricated via spark plasma sintering and their effect on densification was assessed. Subsequently, the electrochemical behaviour of TiC70N30–Gr composites was evaluated in 0.5 mol/L hydrochloric acid (HCl), 0.5 mol/L sulphuric acid (H2SO4) and 0.5 mol/L nitric acid (HNO3) solutions using open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The corrosion behaviour of TiC70N30-based ceramic composites with and without graphite reinforcement exhibited high corrosion resistance in the acidic electrolytes. Composites with 0.5 and 1.0 wt% graphite content showed lower Icorr values of 0.452 µA and 0.081 µA in 0.5 mol/L HCL and 0.5 mol/L HNO3, respectively, while specimen without graphite addition showed better corrosion resistance in 0.5 mol/L H2SO4 (0.041 µA). Based on the corrosion results, the corrosion properties of TiC70N30 ceramic composites in HCl and HNO3 solutions were significantly enhanced upon the incorporation of graphite reinforcements. However, the corrosion test results conducted in H2SO4 solution showed that the addition of graphite had a negligible influence on the corrosion resistance of the titanium carbonitride (TiCN) composites.

Few-layer graphene production through graphite exfoliation in pressurized CO2 assisted by natural surfactant

Graphene research has captivated researchers worldwide, propelling innovation across diverse industries. Through the liquid-phase exfoliation methodology of graphite powder, we have demonstrated a rapid route for obtaining few-layer and multi-layer graphene using a natural surfactant, cardanol. Aqueous phase exfoliation of graphite in the presence of cardanol as a surfactant was conducted to obtain pre-exfoliated graphite suspensions. The influence of different ultrasonication times, 10, 20, and 30 min, and contact times with the surfactant, 1 and 60 min, on the stability and concentration of dispersed exfoliated graphite was evaluated. Results indicate that ultrasonication for 20 min resulted in improved stability and reduced graphene flake sizes, making it suitable for scalable graphene production. Subsequently, the most stable dispersions of exfoliated graphite were subjected to CO2-pressurized treatment. Promising results were obtained when employing cardanol at its critical micelle concentration. The graphene exhibited good structural quality, low defect density, and small stacking, with an average size of 15 nm, where 40 % of the stacked graphene was smaller than 5 nm. The findings provide valuable recommendations for the scalable production of graphene with multilayers and a few layers (FLG/MLG), using cardanol, a friendly surfactant, and a novel method of exfoliation utilizing supercritical CO2. This technology represents an innovative approach, with potential applications in supercapacitors, solar cells, biosensors, polymer composites, and advanced materials.

Synthesis and characteristics of carbon-based synfuel from biomass and coal powder by synergistic co-carbonization technology

A synergistic co-carbonization method based on the use of corn stalk (CS), wood shavings (WS) and bituminous coal (BC) is proposed as a green and low-cost technology. The preparation parameters included a co-carbonization temperature of 600 °C, a co-carbonization time of 30 min, and a biomass/coal ratio of 4/6. The high calorific value (HCV) and bulk density of the CS/BC synfuel were 29.81 MJ kg−1 and 495 kg m−3, respectively, and those of the WS/BC synfuel were 30.11 MJ kg−1 and 485 kg m−3, respectively. The results indicated that the microcrystalline structure was ordered and that the proportion of the graphitic structure increased during the synergistic co-carbonization process. In addition, the co-carbonization process changed the contents of the functional groups on the surface. The amount of aromatic C–O increased during the synergistic co-carbonization process. Decreases in the O-containing functional groups and increases in the graphitic carbon content in the synfuel demonstrated that the interactions of the biomass volatiles with the bituminous coal generated a more regular structure for the carbon-based synfuel and changed the carbon type of the synfuel. This work provides a mechanism for the biomass and coal interactions occurring during the preparation of carbon-based synfuels.

Research on damage optimization of copper-carbon gradient composite materials for current-carrying friction

To meet the demand for damage optimization of current-carrying friction materials and based on the uneven distribution characteristics of damage, copper-graphite gradient composite materials were prepared using spark plasma sintering technology. These materials were paired with H62 brass, conducting damage optimization studies on copper-graphite gradient composite materials using a self-made current-carrying friction test machine. The results indicate that the copper-graphite gradient composite materials possess excellent current-carrying performance. With an increase of graphite content, the degree of mechanical damage and arc damage on the worn surface is optimized. The friction coefficient and wear rate of the material significantly decrease. When the content of graphite in the material is 5 wt% − 10 wt%, The material's damage optimization reaches the best and the wear rate is 9.7 × 10−4 mg·m−1. At this point, the predominant form of damage to the material is plastic deformation.

Effect of graphite content on the microstructure and mechanical properties of SLS-based RB-SiC ceramics

In this study, reactive bonded (RB)-SiC ceramics were fabricated using a combination of selective laser sintering (SLS) and reactive melt infiltration (RMI). The microstructure and mechanical properties of RB-SiC ceramics were optimized by adjusting the graphite content. The sintered bodies were found to consist of α-SiC, β-SiC, Si and C. The addition of graphite prolonged the reaction time between carbon and silicon, resulting in a greater infiltration of molten silicon and an increased formation of β-SiC. Furthermore, a correlation was observed between the proportion of graphite content and the bulk density and bending strength of RB-SiC ceramics. In the range of 0–10 wt%, the bulk density initially increased and then decreased as the graphite content increased. The maximum density was found to be 2.74 ± 0.15 g/cm3. The flexural strength reached the maximum value at 217.9 ± 16.9 MPa when the graphite content was 5 wt%. However, beyond this point, the flexural strength decreased rapidly. The present research demonstrates the promising potential of utilizing SLS additive manufacturing to fabricate SiC ceramics with exceptional mechanical properties.

Modeling and prediction of tribological properties of copper/aluminum-graphite self-lubricating composites using machine learning algorithms

The tribological properties of self-lubricating composites are influenced by many variables and complex mechanisms. Data-driven methods, including machine learning (ML) algorithms, can yield a better comprehensive understanding of complex problems under the influence of multiple parameters, typically for how tribological performances and material properties correlate. Correlation of friction coefficients and wear rates of copper/aluminum-graphite (Cu/Al-graphite) self-lubricating composites with their inherent material properties (composition, lubricant content, particle size, processing process, and interfacial bonding strength) and the variables related to the testing method (normal load, sliding speed, and sliding distance) were analyzed using traditional approaches, followed by modeling and prediction of tribological properties through five different ML algorithms, namely support vector machine (SVM), K-Nearest neighbor (KNN), random forest (RF), eXtreme gradient boosting (XGBoost), and least-squares boosting (LSBoost), based on the tribology experimental data. Results demonstrated that ML models could satisfactorily predict friction coefficient and wear rate from the material properties and testing method variables data. Herein, the LSBoost model based on the integrated learning algorithm presented the best prediction performance for friction coefficients and wear rates, with R2 of 0.9219 and 0.9243, respectively. Feature importance analysis also revealed that the content of graphite and the hardness of the matrix have the greatest influence on the friction coefficients, and the normal load, the content of graphite, and the hardness of the matrix influence the wear rates the most.

Study on friction and wear behavior of gray cast iron with different carbon content at different temperatures

In this paper, we study the friction and wear properties of gray cast iron with different carbon contents at various ambient temperatures. We also examine the failure forms of gray cast iron friction and wear. The research concludes that under low-temperature wear conditions, the graphite in the gray cast iron structure can enter into the interface between the friction pair, have a lubricating effect on the wear surface, and reduce the friction coefficient and wear loss of the gray cast iron material. As the graphite content in the gray cast iron structure increases, its lubrication and protection effects enhance. Consequently, the primary cause of wear failure in gray cast iron is fatigue peeling induced by plastic deformation. Under high-temperature wear conditions, an oxide layer gradually forms on the wear surface. As the experimental temperature increases, the thickness of the oxide layer on the wear surface also increases. When the oxide layer formed on the wear surface reaches a certain level of thickness, the internal expansion stress of the oxide layer increases considerably, causing the oxide layer to peel off and increase the roughness of the wear surface, friction coefficient, and wear loss. Additionally, an increase in the graphite content in the gray cast iron structure makes the surface more prone to oxidation. This leads to increased friction coefficient and wear loss, with the wear failure of gray cast iron primarily caused by the peeling of the oxidation layer.

Synthesis and electrical properties of Reused-Graphite/Polyaniline composites

Polyaniline graphite composites have been synthesized using chemical oxidative polymerization method. The graphite powder has been reused which is obtained by used batteries. XRD patterns of graphite show (002) peak and no impurity peaks. Different wt. % (5, 10, 15, 20) of graphite is used for synthesis of composites and studied their electrical conductivity. XRD patterns of composites show increasing intensity with an increasing graphite content. SEM images show plate-like morphology of graphite whereas granular-morphology for PANI. Composite samples show both plate-like morphology and granular morphology indicating that graphite is embedded in the polymer matrix. Electrical characteristics of composite samples have shown a systematic increase in conductivity with an increase in the graphite concentration. Conductive fillers within the polymer matrix can increase the overall conductivity. Higher filler content provides more conductive pathways for electrons, resulting in enhanced conductivity. The detailed studies of these results are discussed and presented in this paper.

The influence of nitrogen and oxygen on the high nucleation density diamond growth

High nucleation density diamond films were grown on silicon substrates with a high-density nano-diamond suspension crystal seed. By keeping other parameters constant and varying the amounts of oxygen and nitrogen added, diamond films were grown using MPCVD equipment. The composition, structure, and properties of the diamond films were characterized using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results show that the average grain size of samples grown with added oxygen and nitrogen as assisting gases significantly decreased, exhibiting improved crystallinity and fewer defects. However, there was a certain increase in the relative content of graphite, along with the presence of trans-polyacetylene. Furthermore, as the ratio of oxygen to nitrogen increased, the samples exhibited better crystallinity, fewer defects, and overall higher growth quality. The relative content of graphite initially increased, then decreased, and increased again.

Effect of Exothermic Additions in Core Filler on Arc Stability and Microstructure during Self-Shielded, Flux-Cored Arc Welding

In the conditions of an energy crisis, an important issue is the increase in energy efficiency and productivity of welding and hardfacing processes. The article substantiates the perspective of using exothermic additives introduced into core filler for flux-cored wire arc welding processes as a relatively cheap additional heat source, reducing energy consumption when melting filler materials, and increasing the deposition rate. The mixture design (MD) was selected as the design method to optimize the average values of current and voltage, as well as arc stability parameters depending on core filler composition. This article studies the influence of the introduction of exothermic addition (EA), as well as the ratios CuO/C and CuO/Al on arc stability for the FCAW S process. Parameters characterizing arc stability were determined using an oscillograph, and from the obtained oscillograms, an analysis was conducted on arc voltage and welding current signals during flux-cored arc welding. It was determined that various methods can be used to evaluate arc stability, which can be divided into two groups: graphical (current and voltage cyclograms, box plots with frequency histograms, ellipse parameters plotted on current, and voltage cyclograms) and statistical (standard variation and coefficients of variation for welding current and arc voltage). In this paper, a comprehensive evaluation of arc stability depending on the composition of the cored wire filler was carried out. It was determined that the most stable current parameters were observed for the flux-cored wire electrode with an average exothermic addition content at the level of EA = 26.5–28.58 wt.% and a high carbon content (low values of CuO/C = 3.75). Conversely, the lowest values of arc stability (CV(U) and Std(U)) were observed during hardfacing with a flux-cored wire electrode with a high CuO/Al ratio ≥ 4.5 and a content of exothermic addition in the core filler below the average EA < 29 wt.%. Mathematical models of mean values, standard deviation, coefficient of variation for welding current, and arc voltage were developed. The results indicated that the response surface prediction models had good accuracy and prediction ability. The developed mathematical models showed that the ratio of oxidizing agent to reducing agent in the composition of exothermic addition (CuO/Al) had the greatest influence on the welding current and arc voltage characteristics under investigation. The percentage of exothermic mixture in the core filler (EA) only affected the average welding current (Iaw) and the average arc voltage (Uaw). The graphite content expressed through the CuO/C ratio had a significant impact on welding current parameters as well as the coefficient of variation of arc voltage (CV(U)). Two welding parameters were selected for optimization: the mean welding current (Iaw) and the standard deviation of arc voltage (Std(U)). The best arc stability when using exothermic addition CuO-Al in the core filler was observed at CuO/Al = 3.6–3.9, CuO/C = 3.5–4.26, and at an average EA content of 29–38 wt.%. The significant influence of the CuO/Al and CuO/C ratios on arc voltage parameters can also be explained by their impact on the elemental composition of the welding arc (copper, cupric oxide (CuO), and Al2O3). The more complete this reaction, the higher the amount of easily vaporized copper (Cu) in the arc plasma, enhancing arc stability. The influence of core filler composition on the microstructure of deposited metal of the Fe-Cr-Cu-Ti alloy system was investigated.

An ingenious synergistic solid lubricant of copper and graphite for exceptional wear resistance of the SCF/PTFE/PEEK composite

In this work, the conventional short carbon fiber (SCF)/polytetrafluoroethylene (PTFE)/polyetheretherketone(PEEK) (SCF/PTFE/PEEK) composite was elected as the matrix, copper and graphite micron flakes were further blended to prepare PEEK self-lubricating composites. At a pressure of 12 MPa and a speed of 0.5 m/s, with a graphite content of 7.5 wt% and copper of 2.5 wt% (Gr7.5Cu2.5), the composite exhibited a COF of 0.23 and the lowest wear rate of 4.1 × 10−7 mm3/Nm. Physicochemical analysis of the worn surface of the steel ring revealed that the introduction of appropriate amounts of copper facilitated the tribo-physicochemical reaction during the rubbing process, which favored the formation of a thin and tough transfer film of Gr7.5Cu2.5 on the worn surface of the steel ring.

Bayesian Optimization of Environmentally Sustainable Graphene Inks Produced by Wet Jet Milling.

Liquid phase exfoliation (LPE) of graphene is a potentially scalable method to produce conductive graphene inks for printed electronic applications. Among LPE methods, wet jet milling (WJM) is an emerging approach that uses high-speed, turbulent flow to exfoliate graphene nanoplatelets from graphite in a continuous flow manner. Unlike prior WJM work based on toxic, high-boiling-point solvents such as n-methyl-2-pyrollidone (NMP), this study uses the environmentally friendly solvent ethanol and the polymer stabilizer ethyl cellulose (EC). Bayesian optimization and iterative batch sampling are employed to guide the exploration of the experimental phase space (namely, concentrations of graphite and EC in ethanol) in order to identify the Pareto frontier that simultaneously optimizes three performance criteria (graphene yield, conversion rate, and film conductivity). This data-driven strategy identifies vastly different optimal WJM conditions compared to literature precedent, including an optimal loading of 15wt% graphite in ethanol compared to 1wt% graphite in NMP. These WJM conditions provide superlative graphene production rates of 3.2ghr-1 with the resulting graphene nanoplatelets being suitable for screen-printed micro-supercapacitors. Finally, life cycle assessment reveals that ethanol-based WJM graphene exfoliation presents distinct environmental sustainability advantages for greenhouse gas emissions, fossil fuel consumption, and toxicity.

Synthesis of N-doped graphene film with tunable graphitic and pyridinic doping content

Nitrogen-doped (N-doped) graphene films with up to a 17.39 at.% doping level were synthesized with the chemical vapor deposition growth method. An extensive range of tunable nitrogen doping levels was achieved by selecting organic molecules as precursors grown at a wide temperature range of 300 to 1000 °C. The benzene rings in the precursor significantly reduced the energy requirements of N-doped graphene. The incorporation of bridgehead nitrogen and amino groups ensured a high nitrogen doping level and offered the tunable modulation of nitrogen dopant concentrations. The influence of temperature on the nitrogen content was investigated, distinguishing the graphitic and pyridinic dopant types, each demonstrating unique trends considering the dopant stability and growth mechanism. Specifically, the proportion of graphitic doping could be modulated from 40 % to 100 %. Notably, the pyrrolic type was absent at lower temperatures and was nearly negligible at elevated temperatures. Therefore, we developed a synthesis method for N-doped graphene growth that allowed for the selective and prioritized tuning of nitrogen dopant types. This method is particularly favorable when specific nitrogen dopants at certain doping levels are required for electrical and chemical catalytic applications.

The Performance of a Modified Anode Using a Combination of Kaolin and Graphite Nanoparticles in Microbial Fuel Cells.

The bacterial anode in microbial fuel cells was modified by increasing the biofilm's adhesion to the anode material using kaolin and graphite nanoparticles. The MFCs were inoculated with G. sulfurreducens, kaolin (12.5 g·L-1), and three different concentrations of graphite (0.25, 1.25, and 2.5 g·L-1). The modified anode with the graphite nanoparticles (1.25 g·L-1) showed the highest electroactivity and biofilm viability. A potential of 0.59, 0.45, and 0.23 V and a power density of 0.54 W·m-2, 0.3 W·m-2, and 0.2 W·m-2 were obtained by the MFCs based on kaolin-graphite nanoparticles, kaolin, and bare anodes, respectively. The kaolin-graphite anode exhibited the highest Coulombic efficiency (21%) compared with the kaolin (17%) and the bare (14%) anodes. Scanning electron microscopy and confocal laser scanning microscopy revealed a large amount of biofilm on the kaolin-graphite anode. We assume that the graphite nanoparticles increased the charge transfer between the bacteria that are in the biofilm and are far from the anode material. The addition of kaolin and graphite nanoparticles increased the attachment of several bacteria. Thus, for MFCs that are fed with wastewater, the modified anode should be prepared with a pure culture of G. sulfurreducens before adding wastewater that includes non-exoelectrogenic bacteria.