Graphene Research Articles

Investigation of flexible graphene hybrid knitted sensor for joint motion recognition based on convolutional neural network fusion long short-term memory network

Wearable electronics have attracted have attracted widespread attentions for their promising applications in motion monitoring and human-computer interaction. This paper proposes a flexible wearable joint movement intelligent sensing and recognition system to achieve stable and reliable motion feature extraction and recognition. Flexible graphene hybrid knitted sensor were prepared by transferring graphenes (GNs) agent onto stretchable knitted products via a simple spray-drying approach. The small dynamic movement of human joints for the prepared GNs hybrid sensing gloves, elbow pads and knee pads were converted into electrical signals for sensitive detection. The convolutional neural network fusion long short-term memory (CNN-LSTM) network with self-attention mechanism (SAM) is established for feature training and intelligent dynamic recognition of the measured joint information. The interconnected conductive networks endowed knitted sensor with good flexibility and remarkable electrical conductivity of 37 S/m. The unique conductive networks in the fabric offered excellent linearity and repeatable resistance response variation for better detection of joint motion. The resistant signal was analyzed by feature extraction, data correlation capture and time sequence relationship modeling. Finally, the test results show that the proposed CNN-LSTM with SAM network achieves 97%, 96% and 100% correct recognition rates for gesture signals, elbow and wrist signals and knee signals respectively, which is obviously higher than other recognition algorithms. It has great application prospects in the fields of smart wear, medical detection, and smart elderly care.

Electromagnetic interference shielding performance of lightweight aramid nanofiber/graphene composite aerogels

Aramid nanofiber (ANF)/graphene (GN) composite aerogels were fabricated be the ice template following by freeze-drying, and the composite aerogels obtained excellent EMI shielding performance as well as good compression strength and heat resistance.

Development of Carbon Nanotubes–Graphene–Polydimethylsiloxane Composite Film with Excellent Electrothermal Performance

Low power density and low heating rate are the key constraints for the development of conductive polymer materials in the field of electric heating. The carbon nanotubes (CNTs)–graphene (GR)–polydimethylsiloxane (PDMS) composite film was prepared by vacuum filtration and spin coating to solve the problem in this study. Moreover, an AC electric field was used to orient the CNTs to enhance the electrothermal performance. The structure and properties of composite films were analyzed. The results show that the composite film with CNT:GR = 2:1 has the lowest permeation threshold, and can heat up within 30 s and stabilize at 260 °C at 10 V. The electric field-oriented CNTs reduced the insulating polymer layer, increasing the heating rate of the composite film by 1.2 times, and increasing the theoretical thermal conductivity. The flexible electrothermal composite film prepared in this study can be used in thermal insulation, deicing, and wearable electronic devices.

Self-assembly strengthening-toughening epoxy/Graphene composites through intermolecular π-π interactions with ultralow Graphene content

Dispersion of Graphene (GE), high cost of massive usage of GE, and synergistic efficiency of GE and other fillers on epoxy resin (ER) are still challenges. This work not only achieves the uniform dispersion of few-layered GE through π-π interaction between GE and phenyl glycidyl ether (PGE), but also presents an equation in calculating the synergistic efficiency of multiple tougheners. The results show that the strength, modulus, elongation at break, and impact strength of ER can be simultaneously improved when D8 (an epoxy resin with side aliphatic chains) and PGE/GE are used together (D8/PG-X samples) or alone, and the D8/PG-X samples exhibit incomparable positive synergistic efficiency in both strength and toughness with ultralow GE content. The improvement of the impact strength, elongation at break, tensile modulus, and tensile strength in the optimum D8/PG-5 system is 115.5 %, 45.7 %, 17.8 %, and 28.3 % compared with unmodified ER system. We demonstrate that the improved comprehensive properties of the D8/PG-X samples as well as the improved interlaminar shear strength (ILSS) of the carbon fiber (CF)/ER composites can be ascribed to synergistic strengthening-toughening effect of self-assembly effect of aliphatic chains in D8 and uniformed dispersed GE (by π-π interaction). The impressive synergistic strengthening-toughening strategy can provide theoretical guidance for the preparation of high-performance ER with ultralow GE content.

3D-printed stepped structure based on graphene-FeSiAl composites for broadband and wide-angle electromagnetic wave absorption

The design and preparation of absorbers with ultra-wide bandwidth and wide-angle absorption characteristics are crucial technologies for addressing electromagnetic (EM) pollution. In this paper, a stepped structure absorber was fabricated of graphene (GR)-FeSiAl/polylactic acid (PLA) composite by 3D printing technology. The absorber contains four layers, the bottom layer being a slab with periodic square holes, and the upper layer is a periodic distribution of three cubes with equal thickness and gradient changes in side length. It is shown that the stepped structure achieves a minimum reflection loss (RLmin) of −36.01 dB, with an effective absorption bandwidth (EAB, corresponding to the bandwidth of RL < −10 dB) of 12.75 GHz. These results were obtained when the unit cell had a side length of 22.5 mm, the slab thickness was 1.5 mm, and the cube had a thickness and edge length difference of 2.5 mm and 4.0 mm, respectively. Furthermore, the value of EAB is greater than 10 GHz for both transverse electric (TE) polarization and transverse magnetic (TM) polarization when the incident angle changes from 0° to 50°. The broadband and efficient EM wave (EMW) absorption characteristics of this absorber can be attributed to integration of excellent impedance matching and the multi-scale loss mechanisms.

Three-dimensional printed re-entrant strain sensor using various carbon types/thermoplastic polyurethane filaments

In this study, to fabricate a soft conductive re-entrant (RE) strain sensor using a fused filament fabrication three-dimensional (3D) printer, carbon/thermoplastic polyurethane (TPU) filaments with three carbon materials—graphene (GR), carbon fiber (CF), and carbon black (CB)—were analyzed. The 3D printing performance of carbon/TPU was evaluated to confirm the applicability to 3D printing. Firstly, the results of the carbon/TPU filament, morphology, and X-ray diffraction analysis confirmed GR-TPU exhibited crystallinity, and the size of the CB particles was the smallest at &lt;100 nm. For the thermal property, thermogravimetric analysis indicated that the carbon content of CB-TPU was the highest. In addition, differential scanning calorimetry showed that, depending on the carbon material content, the Tg of CB-TPU was the highest. However, since the particles were the smallest, they were easily dispersed and the Tm was the lowest. An analysis of the tensile properties indicated that GR-TPU was the weakest, CF-TPU was hard and brittle, and CB-TPU was the softest and toughest. The conductivity of CB-TPU was 36.12 mA, so it was 25 times higher than the other filaments. The results of the 3D printed RE pattern using various types of carbon/TPU and CB-TPU exhibited the best output performance. The results of the tensile property of the 3D printed RE pattern were similar to those of the filaments. In addition, the conductivities of the 3D printed RE patterns were improved more than the filament status, as ordered during 3D printing. Therefore, 3D printed carbon/TPU can be used as a basis for manufacturing soft sensors.

Two‐Dimensional Conjugated Metal‐Organic Framework/Graphene π–π Stacked Heterostructures for Ultrafast Photonics

Abstract2D conjugated metal‐organic frameworks (MOFs) with high in‐plane‐π‐conjugation are attracting significant attention in various fields owing to their outstanding electrical transport property, substantial specific surface areas, and tunable structures. However, their potential in ultrafast photonics has not been extensively explored. Herein, 2D conjugated Ni3(HITP)2 metal‐organic framework (MOF) and graphene (GR) π–π stacked vertical heterostructures (NG‐VHS) are synthesized using an ultrasound‐assisted method. Based on theoretical simulations and characterization analyses, the results suggest that the fast interface charge transfer and the extension of the π‐conjugated electron cloud will significantly enhance the electrical conductivity and the nonlinear optical properties, which is attributed to the π–π stacking interactions between Ni3(HITP)2 and GR. The charge transfer rate of NG‐VHS is given by 6.9 × 1011 s−1. Noticeably, NG‐VHS can serve as an excellent saturable absorber (SA) that can achieve fundamental mode‐locking with a pulse width of 451 fs, harmonic mode‐locking with repetition frequencies up to 1.205 GHz, and tunable dual‐wavelength mode‐locking. These results indicate the potential of NG‐VHS as a promising nonlinear optical material for ultrafast optical applications and a new platform for the design of advanced optoelectronic devices based on 2D conjugated MOFs.

Waterproof and Flexible Aquatic Tactile Sensor with Interlocked Ripple Structures for Broad Range Force Sensing

AbstractUnderwater perception of a broad range of force holds great importance in aquatic explorative activities, while flexible tactile sensors face technical challenges to realize. This paper presents a novel flexible aquatic tactile sensor based on waterproof graphene (GR)/carbon nanotube (CNT)/Polydimethylsiloxane (PDMS) composites. The prepared GR/CNT/PDMS composites possess excellent hydrophobic and electromechanical properties with a water contact angle over 134° and an ultrahigh gauge factor of 2296, making them an ideal piezoresistive sensing material for underwater broad‐range force sensing. The proposed tactile sensor has 3 × 3 sensing units and uses dual interlocked water‐ripple structures to improve its sensitivity and force detection range. The fabricated tactile sensor is characterized by two distinct sensitivities: a high sensitivity of 0.0338 kPa−1 at 0.062–150 kPa and a low sensitivity of 0.00357 kPa−1 at 150–450 kPa. Further, the sensor exhibited excellent resistance response, fast dynamic recovery, and both mechanical and electrical stability in aquatic environments. Then, the aquatic tactile sensor is worn on the palm of the human hand to detect the distribution and variation of contact forces when grasping objects with different shapes and hardness, demonstrating the potential underwater applications of the developed aquatic tactile sensor for broad‐range force sensing.

Fe3O4/carbon-decorated graphene boosts photothermal conversion and storage of phase change materials

Pristine organic phase change materials (PCMs) are difficult to complete photothermal conversion and storage. To upgrade their photothermal conversion and storage capacity, we developed Fe-MOF (metal-organic framework) derived Fe3O4/C-decorated graphene (GP) based composite PCMs toward solar energy harvesting. Graphene is an excellent phonon conductor, and Fe3O4/C-GP as a photon capturer exhibits strong full-spectrum absorption. Additionally, Fe-MOF derived Fe3O4 nanoparticles are anchored on graphene nanosheets to reduce interfacial thermal resistance, shorten thermal diffusion path, and accelerate phonon transport. After the encapsulation of octadecanol (ODA) in Fe3O4/C-GP, ODA@Fe3O4/C-GP composite PCMs yield a high photothermal conversion efficiency of 88.18 % under 0.12 W/cm2 benefiting from the synergistic effect of 3D interconnected graphene framework and Fe3O4 nanoparticles with localized surface plasmon resonance effect. Moreover, ODA@Fe3O4/C-GP composite PCMs exhibit excellent latent heat storage stability, photothermal conversion stability and durable reliability after undergoing multiple cycle evaluation, boosting high-efficiency utilization of solar energy.

Investigation of the piezoelectric performance of P(VDF-TrFE)/SnO2NPs/GR composite film fabricated via electrospinning

ABSTRACT This paper introduces an innovative sandwich-structured piezoelectric nanogenerator film. In contrast to conventional piezoelectric generators, it exhibits enhanced flexibility and generates higher voltage. It can function as a self-sustaining power source for wearable sensors. To augment the film’s β-phase content, consequently boosting the nanogenerator’s voltage output, the nanofilm was manufactured through high-voltage electrospinning in poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), incorporating stannic oxide nanoparticles (SnO2NPS) and graphene (GR).The relationship between the surface morphology, β-phase content, and voltage output performance of composite piezoelectric films with distinct compositions was comprehensively assessed and scrutinized utilizing scanning electron microscopy (SEM), X-ray diffraction (XRD) patterns, and vibration platforms. The findings reveal that the composition of 12% P(VDF-TrFE) + 5% SnO2NPS + 0.1% GR yields the finest fiber alignment, the highest β-phase content, as well as peak open-circuit voltage and short-circuit peak current values of 22.43 V and 12.95 μA, respectively. This signifies a 1.5-fold and 1.3-fold improvement compared to the film containing only SnO2NPS, and a 2.43-fold and 1.92-fold enhancement relative to the pure P(VDF-TrFE) film. Consequently, it achieves a maximum instantaneous output power of 64.578 μW. Securing the nanogenerator with the aforementioned composition to the sole of a shoe and running for 21 minutes can charge the capacitor to 4 V, thereby empowering it to operate commercial liquid crystal thermometers or approximately 80 LED lights for approximately 1.6 seconds. This technology possesses substantial significance within the realm of self-sustaining low-power electronic devices.

Investigating the optical absorption and thermal conductivity of nano-enhanced lauric acid phase change material for energy storage application

The issue of energy storage can be significantly reduced owing to phase change materials’ (PCMs) tremendous capacity for storing latent heat in a reliable and sustainable method. The limited thermal conductivity, however, prevents PCM from being widely used in a variety of uses. Highly conductive nanoparticles (NPs) are frequently integrated into PCMs to address this shortcoming. Due to their high thermal conductivity, such as Graphene (GR), carbon-based NPs are considered potential NPs to be implemented in PCMs. Herein, we report the Lauric acid (LA) PCM, and nano-enhanced LA with 0.3% and 0.7% additions of GR NPs. The composites were prepared by using two-step method. The samples were examined thermo-physically; thermal conductivity was obtained using a thermal property analyzer (TEMPOs), chemical composition was identified using Fourier transform infrared spectroscopy (FTIR), photo-transmittance by Ultra-Violet Visible spectra (UV-Vis) and thermal stability was assessed by employing thermal gravimetric analyzer (TGA). As per results, thermal conductivity of LA was enhanced by 13.5% and 18.4% by inclusion of 0.3 and 0.7 weight percentages of GR NPs. The 0.7 weight percentage addition of GR NPs to base PCM exhibited 60% transmittance reduction in comparison to base LA. Further all prepared samples were thermally stable with no weight degradation until 140°C. The FTIR confirmed the samples were chemically stable as no any new peak observed in composites. Therefore, based on results, GR enhanced LA PCM can be considered as future potential composite to be implemented in energy storage applications.

Design and application of a flexible nano cardiac sound sensor based on P(VDF-TrFE)/KNN/GR composite piezoelectric film for heart disease diagnosis

The paper proposes a flexible micro-nano composite piezoelectric thin film. This flexible piezoelectric film is fabricated through electrospinning process, utilizing a combination of 12 wt% poly(vinylidene fluoride-co-trifluoroethylene)(P(VDF-TrFE)), 8 wt% potassium sodium niobate (KNN) nanoparticles, and 0.5 wt% graphene (GR). Under cyclic loading, the composite film demonstrates a remarkable increase in open-circuit voltage and short-circuit current, achieving values of 36.1 V and 163.7 uA, respectively. These values are 5.8 times and 3.6 times higher than those observed in the pure P(VDF-TrFE) film. The integration of this piezoelectric film into a wearable flexible heartbeat sensor, coupled with the RepMLP classification model, facilitates heartbeat acquisition and real-time automated diagnosis. After training and validation on a dataset containing 2000 heartbeat samples, the system achieved an accuracy of approximately 99% in two classification of heart sound signals (normal and abnormal). This research substantially enhances the output performance of the piezoelectric film, offering a novel and valuable solution for the application of flexible piezoelectric films in physiological signal detection

Ternary system based on polyaniline, graphene, and acrylic matrix applied to thermoelectric systems

AbstractThermoelectric (TE) materials have attracted attention for offering a green option for power generation, due to their ability to convert thermal energy into electricity. In recent years, a promising way to achieve efficiency in TE properties has been proposed based on composites of conjugated polymers, such as polyaniline (PANI), and carbon nanomaterials such as graphene (GR). Since polyaniline and GR composites are promising fillers for organic thermoelectric materials (OTE), we expanded their investigations for a ternary system (TS), providing materials with multiple functionalities, and high performance. In this research work, a TS based on an acrylic matrix (ACR), GR, and PANI was successfully prepared through the combination of in situ polymerization of aniline in contact with GR and mechanical mixture of the resulting hybrid with an ACR. Structural and morphological characterization confirmed that GR affected PANI morphology and crystallinity. The band gap determination by Tauc's relation indicated the occurrence of π‐π interaction between the chains and an increase of the electrical conductivity of the composites allowed to infer a synergistic effect. The measured Seebeck coefficient reached a maximum value of −17.02 μVK−1 and the highest power factor obtained was 4.94 μWm−1 K−2 for the ACR/PANI sample, indicating a material with promising thermoelectric properties.

Mechanical and conductivity properties of 6061Al matrix composites reinforced with different pH Cu-coated graphene

ABSTRACT The lightweight designs of automobiles and space shuttles have raised the bar for aluminum (Al) and its alloys. Graphene (GP) has found widespread application in aluminum matrix composites due to its exceptional mechanical, electrical, and thermal properties. In this study, a successful preparation of 6061Al reinforced with GP was achieved through a powder metallurgy method. This involved mixing GP with 6061Al alloy powders via ball milling, followed by hot-pressing sintering to produce the final GP-reinforced Al alloy nanocomposite. The effect of the pH value of the plating solution on the electroless plating of GP has been studied for the first time. The results show that the strength of the aluminum-matrix composites with copper plating has been significantly improved compared with that of the composites without copper plating. When the pH value of the plating solution is 12, the tensile strength of the composites obtained has been increased by 60.41%. Compared with the matrix material, the conductivity of the composite material has also increased. This work shows that the mechanical behavior of graphene-reinforced metal matrix composites (MMCs) can be improved by adjusting the distribution of graphene coatings, which is of great benefit for the preparation of high strength and lightweight composites with good electrical conductivity.

Lowering polycyclic aromatic hydrocarbon concentrations in vegetable oil deodorizer distillates and enhancing its utilization by graphene composites

Vegetable oil deodorizer distillates (VODDs), which are the main source of natural tocopherol, are easily contaminated by polycyclic aromatic hydrocarbons (PAHs), and pose health threats to human beings. To remove 16 priority-control PAHs in VODD, three graphene (GR) composites, including TiO2-GR, sepiolite-GR and Fe3O4-GR, were prepared. PAH concentrations and removal rates were determined using gas chromatography-mass spectrum (GC-MS). Additionally, density functional theory (DFT) calculation was conducted to simulate and illustrate PAH adsorption on GR composites. The results indicated that the highest BaP removal rate was given to TiO2-GR with 90.37 ± 3.23 % after 2 h in standard solution. The adsorption followed the pseudo-first order kinetic, with the constant of −0.0141. In contrast, 61.62 ± 7.88 % total PAHs were removed in VODD using TiO2-GR. Moreover, DFT calculation verified that the strongest adsorption effect occurred between TiO2-GR and PAHs, with the adsorption energy of −2.69 eV. Additionally, GR composite morphology would be changed when LPAH concentrations are higher than 30 μg kg-1. The results also indicated the retention rates tocopherol ranged from 91.91 ± 1.92 % to 99.22 ± 0.88 %. This study firstly provides a useful tool for PAH removal in VODDs while retaining tocopherol. Moreover, it will increase the understanding of adsorption process between PAHs and GR composites.

A comparative study of graphite and graphene sheets employed in polymer‐based electromagnetic shielding materials

AbstractIn this work, the comparative properties of graphite (GT) and graphene (GE) sheets for use in polymer‐based electromagnetic (EM) shielding materials were explored. To accomplish this, GT and GE were individually combined with polyvinylidene fluoride (PVDF) as composite films and each was later attached to a nonwoven fabric to produce nonwoven‐reinforced (NR) films. The microtopography showed that GT was easily wrapped by the PVDF matrix in the composite film, whereas GE was partially exposed on the film surface because of its complete contact with PVDF. Addition of the carbon materials appeared to increase the EM shielding effectiveness (SE) of the films in the X‐band. The SE of the PVDF/GE films was significantly higher than the PVDF/GT films, up to 50.4 dB, which was mainly affected by electronic conductivity. The internal loss of the EM wave in PVDF/GE films was dominated by internal reflection because of the more regular arrangement of GE, whereas the loss in the PVDF/GT films contained greater EM absorption. Although the SE at 1–18 GHz of NR PVDF/GT film was significantly lower than the NR PVDF/GE film, the internal loss at high frequency was higher due to the better absorption loss in its surface layer.Highlights GT and GE sheets were compared as functional materials. GT and GE sheets showed different distribution states in the films. The EM SE of the PVDF/GE films was up to 50.4 dB. The EM shielding mechanism was analyzed and compared.

Designing Multielement nanointerfaces in supported catalysts by ultra small lattice mismatch

Catalysts supported by multiple functional constituents show exceptional catalytic performance, attributed to electron and energy exchanges occurring at the nanointerfaces between different subunits. Herein, the lattice-mismatch mechanism was used to guide the creation of a functional interface between cobalt oxide (CoO) and zinc oxide (ZnO) on a graphene (GN) support. By computing the lattice-mismatch between hexagonal wurtzite CoO (h-CoO) and ZnO, we achieve an exceptionally low value of 0.18 %. This ultra small lattice-mismatch facilitates the formation of interfaces when employing a seed-mediated growth approach, using a colloidal method for catalyst design. In this approach, CoO is expected to grow directly on ZnO particles, rather than on GN, when utilizing the ZnO/GN catalyst as heteroseed. The growth pattern of CoO follows the Frank − van der Merwe (FM) model, leading to the successful preparation of ZnO@CoO/GN. Similarly, ZnO readily interfaces with the CoO surface to form a nanointerface when the ZnO@CoO/GN catalyst is used as the seed. Interestingly, this epitaxial growth process can be repeated multiple times, resulting in increasingly diverse nano-heterostructures. The resulting catalyst exhibits outstanding performance in CO2 hydrogenation reaction due to the presence of dense CoO-ZnO nanointerfaces. The methodology presents a novel concept for the advancement of efficient supported catalysts.

Optimization of Piezoresistive Response of Elastomeric Porous Structures Based on Carbon-Based Hybrid Fillers Created by Selective Laser Sintering.

Recently, piezoresistive sensors made by 3D printing have gained considerable interest in the field of wearable electronics due to their ultralight nature, high compressibility, robustness, and excellent electromechanical properties. In this work, building on previous results on the Selective Laser Sintering (SLS) of porous systems based on thermoplastic polyurethane (TPU) and graphene (GE)/carbon nanotubes (MWCNT) as carbon conductive fillers, the effect of variables such as thickness, diameter, and porosity of 3D printed disks is thoroughly studied with the aim of optimizing their piezoresistive performance. The resulting system is a disk with a diameter of 13 mm and a thickness of 0.3 mm endowed with optimal reproducibility, sensitivity, and linearity of the electrical signal. Dynamic compressive strength tests conducted on the proposed 3D printed sensors reveal a linear piezoresistive response in the range of 0.1-2 N compressive load. In addition, the optimized system is characterized at a high load frequency (2 Hz), and the stability and sensitivity of the electrical signal are evaluated. Finally, an application test demonstrates the ability of this system to be used as a real-time wearable pressure sensor for applications in prosthetics, consumer products, and personalized health-monitoring systems.

GR-Fe3O4/PLA 3D printing composite materials with excellent microwave absorption properties

In this work, composite microspheres were formed by integrating graphene (GR) and Fe3O4 into an ethylcellulose matrix via an emulsion emulsification reaction. Composite wires were fabricated using a melt extrusion process and composite samples were subsequently prepared via a melt molding method. A systematic study was conducted to investigate the absorption performance of GR-Fe3O4/PLA (Polylactic acid) composite materials. The findings revealed that the optimal microwave absorption performance was achieved when the graphene content was 5.6 wt% and the Fe3O4 content was 11.1 wt%. The maximum reflection loss was − 51.13 dB at a thickness of 2.65 mm. The maximum absorption bandwidth was 4.16 GHz, and the effective radar interception cross-section was reduced to − 42.7 dBm2. The excellent performance of GR-Fe3O4/PLA composite material can be attributed to good impedance matching and the synergistic effect of conductive loss, dipole polarization, interface polarization, and eddy current loss. Then the contribution of conductive loss and polarization loss to the absorption performance was explored. This work provides a novel approach to advance the design and development of functional materials for efficient electromagnetic absorption, providing valuable insights into the development of efficient, lightweight microwave absorbing material.

Screening for the adsorption-activated H2O2 and peroxymonosulfate for high-performance heteroatom-doped graphene: Molecular dynamics simulation and DFT

As an green and efficient metal-free catalyst, heteroatom-doped graphene has gradually become a research topic in the catalytic field, but the active sites and mechanisms of the catalytic reactions are still not thorough enough. In this paper, the adsorption-activation properties of two activated molecules, H2O2 and peroxymonosulfate (PMS), on graphene (GR) and heteroatom (N, P, B, Si, F) doped graphene were investigated by means of computational methods. Molecular dynamics (MD) simulation results showed that the adsorption activation process of activated molecules on the surface of the six catalysts occurs in their first adsorption layer, in which B-doped graphene (BGR) has better catalytic activation performance for H2O2, while N-doped graphene (NGR) has better catalytic activation performance for PMS. Density function theory (DFT) revealed that the lowest molecular orbital gap of H2O2 at -BCO2 (0.691 eV), PMS at -NC2 has the lowest gap (0.432 eV). It is inferred that -BCO2 and -NC2 functional groups are the main functional regions of H2O2 activation by BGR and PMS activation by NGR, respectively. This work provides useful guidance for the design and optimization of high-performance metal-free catalysts, and the realization of green remediation for wastewater in the electrocatalytic oxidation process.