Highly dispersed MnO nanoparticles supported on N-doped rGO as an efficient oxygen reduction electrocatalyst via high-temperature pyrolysis

Transition metal-based compounds, due to their excellent ORR catalytic performance under alkaline condition, have recently emerged as one of the most promising alternatives to noble metal-based ORR catalysts. It is worth noting that manganese oxide can take an unique advantage for decomposition of intermediate adsorption products H₂O₂ and can effectively reduce O₂ to OH⁻. However, most research has focused on MnO₂, while attention has rarely been paid to MnO catalysts. In addition, under high-temperature pyrolysis condition, MnO is the most stable manganese oxide but MnO nanoparticles easily agglomerate. Hence, it is very difficult to obtain well-dispersed and small-sized MnO nanoparticles. Herein, on the basis of pre-synthesizing uniformly distributed manganese complexes on the reduced graphene oxide (rGO), we innovatively prepare highly dispersed and small-sized MnO nanoparticles (~3.94 nm) via high-temperature pyrolysis, which are uniformly anchored on N-doped reduced graphene oxide (NrGO) as an efficient oxygen reduction electrocatalyst. The as-obtained MnO/NrGO (1050 °C) electrocatalyst achieves satisfactory onset potential (0.942 V) and half-wave potential (0.820 V) under alkaline condition. And the limiting current density is 4.17 mA cm⁻², which is very close to that of Pt/C (20 wt%, JM). Meanwhile, MnO/NrGO (1050 °C) catalyst presents superior longstanding durability and methanol resistance than Pt/C (JM). This work indicates that high-temperature pyrolysis can improve the purity of manganese oxide, simultaneously the defects of NrGO can reduce particle size of MnO nanoparticles, which are greatly beneficial to improve ORR performance. This work provides a new idea for research of MnO catalysts for ORR in the future.     

One-step preparation of Fe-doped Ni3S2/rGO@NF electrode and its superior OER performances

In order to improve the OER performance, Ni₃S₂-based catalysts were directly grown on Ni substrate by simultaneously doping of Fe and compositing with reduced graphene oxide (rGO). Synthesis and loading of Ni₃S₂/rGO were completed during a one-step hydrothermal process, in which Ni foam acted as support and Ni source of Ni₃S₂, as well as the subsequent current collector. It is found that either GO or Fe salt tuned Ni₃S₂ nanosheets into thinner and smaller interconnected nanosheets anchored on rGO, which enhanced the charge transfer resistance and improved the active sites. Hence, as-synthesized Fe-doped Ni₃S₂/rGO composite at 120 °C (Fe-2-Ni₃S₂/rGO@NF-120) exhibited an enhancement on OER performances: An overpotential of 247 mV at 20 mA cm⁻², and a small Tafel slope of 63 mV dec⁻¹, as well as an excellent stability of: 20 h maintaining at 20 mA cm⁻² or 50 mA cm⁻².     

One-step hydrothermal preparation of bi-functional NiS2/reduced graphene oxide composite electrode material for dye-sensitized solar cells and supercapacitors

To screen out suitable electrode materials and overcome the shortcomings of the existed electrode materials for the application in dye-sensitized solar cells and supercapacitors, NiS₂/reduced graphene oxide (NiS₂/rGO) composite material was prepared by a simple one-step hydrothermal method in this paper and applied in the field of both dye-sensitized solar cells and supercapacitors as electrode material. In an electrolyte of 6 M KOH, the NiS₂/rGO composite material with bilayer capacitance characteristics exhibited a high specific capacitance of 259.20 F g⁻¹ at the current density of 0.6 A g⁻¹, which was significantly higher than that of rGO (188.94 F g⁻¹). Moreover, at a current density of 2 A g⁻¹, the NiS₂/rGO composite material had 92.85% capacitance retention after 2000 cycles. When applied as counter electrode material for the dye-sensitized solar cells, the NiS₂/rGO composite material counter electrode exhibited a satisfactory photoelectric conversion efficiency (η) of 3.16% under standard simulated sunlight (AM 1.5 G), which was significantly higher than that of single rGO counter electrode (improved by 90.40%). The NiS₂/rGO composite electrode material prepared by a simple one-step hydrothermal method is a potential bi-functional composite electrode materials for both dye-sensitized solar cells and supercapacitors.     

Hierarchical design of Ni(OH)2/MnMoO4 composite on reduced graphene oxide/Ni foam for high-performances battery-supercapacitors hybrid device

Design and synthesis advanced battery-type electrode materials with outstanding electrical conductivity and remarkable theoretical specific capacity are crucial to enhance the comprehensive performances for battery-supercapacitors (SCs). Herein, Ni(OH)₂/MnMoO₄ composite on reduced graphene oxide/Ni foam (rGO/NF) was successfully fabricated through the hydrothermal method and potentiostatic electrodeposition (Ni(OH)₂/MnMoO₄/rGO/NF). The unique honeycomb structure and the efficient synergistic effects among MnMoO₄ and Ni(OH)₂ of the as-prepared battery type electrode, as well as outstanding electronic conductivity of the reduced graphene oxide, were beneficial to the enhanced electrochemically active sites and increased specific capacity. Ni(OH)₂/MnMoO₄/rGO/NF composite employed for SCs yielded the maximum specific capacity of 1329.1 C g⁻¹ and a superb cycle property of 86.8% during 5000 cycles. Furthermore, the battery-supercapacitor hybrid (BSH) device with the Ni(OH)₂/MnMoO₄/rGO/NF and active carbon (AC) as-prepared samples showed the energy density of 61.4 W h kg⁻¹ at the power density of 428.4 W kg⁻¹. The capacity retention of the as-fabricated hybrid device reached 96.4% over 7000 cycles. Those consequences tested that the Ni(OH)₂/MnMoO₄/rGO/NF composite should be the promising category of battery-type electrodes materials of the next generation energy storage devices for the high-performances SCs.     

Energy storage of thermally reduced graphene oxide

The energy-storage capacity of reduced graphene oxide (rGO) is investigated in this study. The rGO used here was prepared by thermal annealing under a nitrogen atmosphere at various temperatures (300, 400, 500 and 600 °C). We measured high-pressure H₂ isotherms at 77 K and the electrochemical performance of four rGO samples as anode materials in Li-ion batteries (LIBs). A maximum H₂ storage capacity of ∼5.0 wt% and a reversible charge/discharge capacity of 1220 mAh/g at a current density of 30 mA/g were achieved with rGO annealed at 400 °C with a pore size of approximately 6.7 Å. Thus, an optimal pore size exists for hydrogen and lithium storage, which is similar to the optimum interlayer distance (6.5 Å) of graphene oxide for hydrogen storage applications.     

A hybrid PEMFC/supercapacitor device with high energy and power densities based on reduced graphene oxide/Nafion/Pt electrode

Proton exchange membrane fuel cells (PEMFCs) possess high energy and low power densities, while supercapacitors are characterized by high power and low energy densities. A hybrid PEMFC/supercapacitor device (HPSD) with high energy and power densities was proposed and fabricated for the first time using a reduced graphene oxide/Nafion/Pt electrode in this study. The reduced graphene oxide (rGO) was a capacitive material, and Pt was used as the electrocatalyst. Nafion ionomers adsorbed onto the rGO sheets surface and connected the rGO sheets and the electrolyte (Nafion membrane), thus increasing the utilization rate and specific capacitance of rGO. During the half-cell tests, the rGO/Nafion/Pt electrode exhibited better pulse discharge and galvanostatic discharge performance than the conventional Nafion/Pt electrode. Due to the unique synergy of electrochemical reaction current and capacitance current during the discharge process, the HPSD exhibited a higher power density (26.2 kW kg⁻¹) than the PEMFC (23.9 kW kg⁻¹). The energy density (12.7 kWh kg⁻¹) exhibited by HPSD was close to that of the PEMFC (13.5 kWh kg⁻¹). Therefore, the concept of HPSD is to create a new method for developing next-generation electrochemical devices with high energy and power densities.     

In situ growth of Ni0·85Se on graphene as a robust electrocatalyst for hydrogen evolution reaction

Seeking the efficient and robust electrocatalysts necessarily enhances performance of hydrogen evolution reaction (HER). Increasing the surface active sites is a means to improve the performance. Herein, we use the Ni_0·85Se anchored on reduction of graphene oxide (Ni_0·85Se/rGO) hybrid material skillfully established by one-step facile hydrothermal method as a robust and stable electrocatalyst applying to hydrogen evolution reaction (HER). In terms of morphology, Ni_0·85Se nanospheres composed of many nanosheets are uniformly distributed on the graphene sheet layer. We also detailedly analyze its properties. Based on the interaction between Ni_0·85Se and rGO, and the roles of graphene are as a substrate to heighten conductivity, possesses more active surface area by limiting growth of Ni_0·85Se, and increases dispersion for exposing more active surface area and enlarge ion/electron transfer rate. In HER, the Ni_0·85Se/rGO catalyst displays the overpotential of 128 mV with a common current density of 10 mA cm⁻², a small Tafel slope of 91 mV dec⁻¹, an extremely low onset potential of 37 mV, outstanding stability that a high current retention of 97.7% after 1000 cycles and well long-term stability for 18 h, outperforming the capability of Ni_0·85Se nanospheres in alkaline solution for HER. The above results indicate that the Ni_0·85Se/rGO hybrid material is a good HER ability and non-noble metal electrocatalyst has potential value in HER.     

Defect locating: One-step to monodispersed CoFe2O4/rGO nanoparticles for oxygen reduction and oxygen evolution

In this work, monodispersed CoFe₂O₄/reduced graphene oxide (rGO) nanoparticles have been successfully synthetized in one step from Co(Ⅱ) acetylacetonate, Fe(Ⅲ) acetylacetonate, benzylamine and graphene oxide (GO). A facile solvent method was designed to skillfully integrate the crystal growth process of CoFe₂O₄, the reduction process of GO and their compound process. In synthesis process, large numbers of defects on GO thin layers were smartly used to disperse CoFe₂O₄ nanoparticles. The micromorphology and the distribution of as-prepared samples were identified via X-ray diffraction (XRD), transmission electron microscope (TEM) and element mapping spectra. Results showed that the monodispersed CoFe₂O₄ nanoparticles were uniformly coupled with rGO thin layers. Good performance for both oxygen reduction and oxygen evolution of as-prepared CoFe₂O₄/rGO (0.92 V onset potential for oxygen reduction and 1.59 V overpotential at 10 mA cm⁻² for oxygen evolution, vs. RHE) were found during a series of electrochemical tests, which make it a promising bi-functional catalyst in the field of fuel cells and metal-air batteries.     

Solvothermal synthesis of Pd10–Ni45–Co45/rGO composites as novel electrocatalysts for enhancement of the performance of DBFC

In this research, three Pd decorated Ni and Co catalyst nanoparticle were synthesized on reduced graphene oxide (rGO) supports are synthesized through a facile solvothermal procedure. Borohydride oxidation reaction (BOR) activity and performance of prepared electrocatalysts respect to NaBH₄ oxidation is evaluated by various electrochemical techniques in the three-electrode and the fuel cell configuration. Among the prepared catalysts, Pd₁₀–Ni₄₅–Co₄₅/rGO exhibits the highest BOR activity. The cyclic voltammograms showed that the measured current at 0.5 V for the electrode of Pd₁₀–Ni₄₅–Co₄₅/rGO is as much as 108 mA cm⁻² higher than Pd₁₀–Ni₉₀/rGO and 185 mA cm⁻² higher than Pd₁₀Co₉₀/rGO. X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra were employed to study the morphology and crystal structure of the prepared catalyst. The results of DBFC test show that the Pd₁₀–Ni₄₅–Co₄₅/rGO nanoparticles as anodic catalyst, enhanced power density to 50.4 mW cm⁻² which is 10.5% and 45.2% higher than power density of DBFCs with Pd₁₀–Ni₉₀/rGO (45.6 mW cm⁻²) and Pd₁₀Co₉₀/rGO (34.7 mW cm⁻²) anode catalysts, respectively. These results indicate that the competency of operating procedure for assembling nickel alloys electrodes can improve the activity of the prepared catalysts for BOR considerably.     

Sm2O3 promoted Pd/rGO electrocatalyst for formic acid oxidation

Herein, we report the synthesis of Sm₂O₃ incorporated palladium based electrocatalyst, supported over reduced graphene oxide (rGO). Pd_xSm_y nanoparticles (20 wt %) are distributed over rGO surface by using sodium borohydride reduction technique. Different physicochemical analyses are used to characterize the Pd_xSm_y/rGO electro-catalysts (x = 2,4,6 and y = 8,6,4). The synthesized materials (Pd_xSm_y/rGOs) are investigated for their catalytic capabilities toward electro-oxidation of formic acid. The results show that adding Sm₂O₃ to the Pd/rGO electrocatalyst boosts electrochemical activities of the materials toward formic acid oxidation. The optimized catalyst (Pd₆Sm₄/rGO) shows excellent activity towards formic acid oxidation with current density of 46.70 mA/cm² compared to reference catalysts i.e., Pd/rGO (28.78 mA/cm²) and Pd/C (22.22 mA/cm²). The optimized catalyst also demonstrates high CO tolerance and great stability during formic acid oxidation reaction. The enhanced activity and stability are attributed to the synergistic interaction between Sm₂O_3, and palladium nanoparticles supported over reduced graphene oxide.     

3-Dimensional flower-like clusters of CoNiP nanofoils in-situ grown on randomly-dispersed rGO-Nanosheets with superior electrocatalysis for hydrogen evolution reactions

It has been being an interesting challenge to develop novel electrocatalysts with advantageous nanostructures and thereby-improved catalytic performance for hydrogen evolution reaction (HER) over the past years. Herein, we report on the flower-like clusters of CoNiP nanofoils thickly grown on the randomly-interconnected reduced graphene oxide (rGO) nanosheets (CoNiP-NF/rGO) of 3-dimensional framework architecture, which has been successfully achieved via an optimized solvothermal process with Ni-doped ZIF-67 (Ni-ZIF-67) dodecahedral particles as the precursor and graphene oxide (GO) nanosheets as the substrate for the in-situ growth of flower-like CoNi-hydroxides nanofoils, as well as a following topotactic transformation in a controlled phosphorization. Benefiting from its distinctly advantageous nanostructures featured with extremely high specific surface area, enriched catalytic active sites and enhanced electronic transportation, the as-prepared CoNiP-NF/rGO exhibits an excellent electrocatalytic performance of HER with an onset overpotential of 33 mV, an overpotential of 82 mV at 10 mA cm⁻², a Tafel slope of 37 mV dec⁻¹ and a high chemical stability in acidic solutions. Such an advantageous nanostructure and its positive influences on the electrocatalytic performance are useful for the preparation of other nonprecious metal electrocatalysts.     

Fabrication of electrochemically interconnected MoO3/GO/MWCNTs/graphite sheets for high performance all-solid-state symmetric supercapacitor

Binder-free MoO₃/GO/MWCNTs/graphite sheets were successfully fabricated via electrodeposition of graphene oxide and functionalized multi walled carbon nanotube onto graphite sheets followed by electrodeposition of molybdenum oxide. The capacitive behavior of the MoO₃/GO/MWCNTs/G sheet was found to be superior with respect to those of MoO₃/MWCNTs/graphite and MoO₃/GO/G sheets. The high wettability, interconnected structure and synergetic effects between MoO₃, GO and MWCNTs made the MoO₃/GO/MWCNTs/G sheet exhibited a high areal capacitance of 103 mF cm⁻² at current density of 0.7 mA cm⁻² in 1.0 M KCl. An all-solid-state symmetric supercapacitor device prepared by using the MoO₃/GO/MWCNTs/G sheet as both positive and negative electrodes showed high cell voltage of 2.5 V and remarkable cycle life of 86.8% retention after 2000 cycles, suggesting the possibility for practical applications in energy storage device.     

Boosted 2D graphene nanosheets by organic-inorganic hybrid cross-linker for an efficient and stable supercapacitor

Using covalent graphene derivatives in energy storage applications is promising. From this view, covalently cross-linked graphene oxide (GO) nanosheets are designed using polyoligomeric silsesquioxanes-propyl-NH₂ (POPN). Then, by incorporating cobalt sulfide nanoparticles into the porous scaffold, a high-value nanocomposite is formed. In a typical three-electrode cell, this nanocomposite declared substantial specific capacity of 454 and 438 Fg^-1 using cyclic voltammetry (CV) and charge-discharge (GCD) assessments. The device is assembled via two identical electrodes containing RGO-SiO₃-NH2-poss-NH2-SiO₃-RGO/cobalt sulfide (RGO-Si-POPN-Si-RGO/CoS₂). Utilizing CV and GCD methods, specific capacitances of 328 and 315 Fg^-1 are realized at a sweep rate and current density of 2 mVs^?1 and 0.5 Ag^-1, respectively. The device presents desirable energy density of 18.5 Whkg^?1 at the power density of 325 Wkg^-1. More impressively, around 97.9% of the specific capacitance is retained after 5000 charge-discharge cycles. The results confirm exceptional capacitive capabilities and super stability of the nanocomposite suitable for practical systems.     

Co2FeO4@rGO composite: Towards trifunctional water splitting in alkaline media

Development of efficient, low cost and multifunctional electrocatalysts for water splitting to harvest hydrogen fuels is a challenging task, but the combination of carbon materials with transition metal-based compounds is providing a unique and attractive strategy. Herein, composite systems based on cobalt ferrite oxide-reduced graphene oxide (Co₂FeO₄) @(rGO) using simultaneous hydrothermal and chemical reduction methods have been prepared. The proposed study eliminates one step associated with the conversion of GO into rGO as it uses direct GO during the synthesis of cobalt ferrite oxide, consequently rGO based hybrid system is achieved in-situ significantly, the optimized Co₂FeO₄@rGO composite has revealed an outstanding multifunctional applications related to both oxygen evolution reaction (OER) and hydrogen counterpart (HER). Various metal oxidation states and oxygen vacancies at the surface of Co₂FeO₄@rGO composites guided the multifunctional surface properties. The optimized Co₂FeO₄@rGO composite presents excellent multifunctional properties with onset potential of 0.60 V for ORR, an overpotential of 240 mV at a 20 mAcm^?2 for OER and 320 mV at a 10 mAcm^?2 for HER respectively. Results revealed that these multifunctional properties of the optimized Co₂FeO₄@ rGO composite are associated with high electrical conductivity, high density of active sites, crystal defects, oxygen vacancies, and favorable electronic structure arisinng from the substitution of Fe for Co atoms in binary spinel oxide phase. These surface features synergistically uplifted the electrocatalytic properties of Co₂FeO₄@rGO composites. The multifunctional properties of the Co₂FeO₄@ rGO composite could be of high interest for its use in a wide range of applications in sustainable and renewable energy fields.     

Synthesis of high performing Cu0.31Ni0.69O/rGO hybrid for oxygen reduction reaction in alkaline medium

In this feature article, Cu_0.31Ni_0.69O nanoparticles were assembled on reduced graphene nanosheets (Cu_0.31Ni_0.69O/rGO) by a simple hydrothermal method. The structural characterizations confirm that the synthesized nanoparticles with an average size around 9 nm are densely and uniformly assembled on the reduced graphene oxide (rGO) nanosheets. The electrochemical measurements demonstrate that the as-synthesized Cu_0.31Ni_0.69O/rGO catalyst exhibits excellent catalytic performance for oxygen reduction reaction with high cathodic current density (2.08 × 10⁻⁴ mA/cm²), positive onset potential (−0.21 V), low H₂O₂ yielding rate (less than 2.5%) and long-term running stability. The rotating disk and rotating ring-disk electrode measurements proved that the oxygen reduction reaction occurs on Cu_0.31Ni_0.69O/rGO through a high efficient four-electron pathway. The Cu_0.31Ni_0.69O/rGO nanoparticles shows great potential to be promising noble metal-free catalyst for cathodes of alkaline fuel cells.     

Pd electrodeposition on a novel substrate of reduced graphene oxide/ poly(melem-formaldehyde) nanocomposite as an active and stable catalyst for ethanol electrooxidation in alkaline media

Palladium nanoparticles (Pd NPs) were successfully electrodeposited on a reduced graphene oxide/poly(melem-formaldehyde) nanocomposite (rGO/PMF) NC as a catalyst for ethanol electrooxidation in alkaline media; melem was used as a nitrogen-rich source in the substrate structure for the first time. The specific surface area and average pore diameter of (rGO/PMF) NC were 481.61 m² gr^?1 and 10.23 nm, respectively. High nitrogen doping and structural defects improved the dispersion and anchoring of Pd NPs on (rGO/PMF) NC. The onset potential (E_onset) of Pd/(rGO/PMF) NC was shifted negatively to 110 mV, in comparison to Pd/rGO. Also, the current density and electrochemical active surface area (EASA) of Pd/(rGO/PMF) NC were enhanced to 44 mA cm^?2 and 67.58 m² gr^?1, respectively, as compared to Pd/rGO. Furthermore, the stability of Pd/(rGO/PMF)NC was indicated against ethanol oxidation intermediates during 7000 s. This work also produced a superior graphene-based material for direct ethanol fuel cell anode catalysts applications.     

Reduced CoFe2O4/graphene composite with rich oxygen vacancies as a high efficient electrocatalyst for oxygen evolution reaction

Oxygen evolution reaction (OER) is regarded as a limit-efficiency process in electrochemical water splitting generally, which needs to develop the effective and low-cost non-noble metal electrocatalysts. Oxygen vacancies have been verified to be beneficial to enhance the electrocatalytic performance of catalysts. Herein, we report the facile synthesis of reduced CoFe₂O₄/graphene (r-CFO/rGO) composite with rich oxygen vacancies by a citric acid assisted sol-gel method, heat treatment process and the sodium borohydride (NaBH₄) reduction. The introduction of graphene and freezing dry technique prevents the restacking of GO and the aggregation of CFO nanoparticles (NPs) and increases the electronic conductivity of the catalyst. Fast heating rate and low anneal temperature favors to obtain low crystallinity and lattice defects for CFO. NaBH₄ reduction treatment further creates the rich oxygen vacancies and electrocatalytic active sites. The obtained r-CFO/rGO with high specific surface area (108 m² g⁻¹), low crystallinity and rich oxygen vacancies demonstrates a superior electrocatalytic activity with the smaller Tafel slope (68 mV dec⁻¹), lower overpotential (300 mV) at the current density of 10 mA cm⁻², and higher durability compared with the commercial RuO₂ catalyst. This green, low-cost method can be extended to fabricate similar composites with rich defects for wide applications.     

An efficient tri-metallic anodic electrocatalyst for urea electro-oxidation

Tri-metallic MnNiFe alloy nanoparticles with four different Mn:Ni:Fe weight ratios (0.5:2.0:0.5, 0.5:1.0:0.5, 1.0:1.0:1.0, and 2.0:0.5:2.0) on reduced graphene oxide (rGO) supports were synthesized using a one-pot hydrothermal method. The as-prepared catalysts were characterized by X-ray diffraction, inductively coupled plasma-mass spectroscopy, Brunauer-Emmett-Teller analysis, scanning electron microscopy, and transmission electron microscopy, and their catalytic activities were measured by cyclic voltammetry and chronoamperometry. In urea electro-oxidation, the Mn_0.5Ni_2.0Fe_0.5/rGO catalyst exhibited superior electrocatalytic activity compared to Ni/rGO and commercial Ni/C. The Mn_0.5Ni_2.0Fe_0.5/rGO catalyst exhibited a mass activity of 1753.97 mA mg⁻¹_Ni, along with an onset potential of 0.34 V (vs. Ag/AgCl) in 1.0 M KOH and 0.33 M urea solution, which is ~4.2 times and 9.8 times higher than those of Ni/rGO and commercial Ni/C, respectively. Furthermore, a single cell comprising of Mn_0.5Ni_2.0Fe_0.5/rGO catalyst exhibited a peak power density of 30.08 mW cm⁻² in 0.33 M urea and 1.0 M KOH at 50 °C.     

Preparation of functional copolymer based composite membranes containing graphene oxide showing improved electrochemical properties and fuel cell performance

The objective of this work is to prepare a functional copolymer of poly(acrylonitrile)-co-poly(2-Acrylamido-2-methyl-1-propanesulfonic acid) (PAN-co-PAMPS) and impregnation of graphene oxide (GO) into the copolymer followed by crosslinking to prepare conetwork composite membranes by simple and cost effective solution casting method and evaluating their structural, morphological, thermal, and mechanical properties. The successful incorporation of different amounts of GO content (0.1–1 wt%) within the polymer matrix was confirmed by FT-IR spectroscopy, X-ray diffraction, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The mechanical properties of the prepared crosslinked composite membranes are found to be greatly enhanced by the addition of GO in the copolymer matrix. The thermogravimetric analysis (TGA) demonstrated considerable improvements in thermal stability for the composite membrane with low GO content. The effect of loading of GO in the copolymer matrix on proton conductivity and fuel cell performance has been studied systematically. The membranes prepared by mixing with 0.5 wt% GO in the copolymer followed by crosslinking exhibited maximum ionic conductivity (K^m), lower methanol permeability (P_M), and higher relative selectivity. This observed P_M value is much lower range from 3.02 × 10^?7 to 11.9 × 10^?7 cm²/s compared to the Nafion® 117 membrane (22 × 10^?7 cm²/s). The fuel cell performance in terms of maximum power density and current density and the durability of the crosslinked composite membranes have also been evaluated here. Low P_M, high K^m, and high selectivity values show that functional co-polymer/GO crosslinked co-network composite membrane is a promising alternative membrane separator to replace the expensive Nafion® 117 for proton exchange membrane fuel cells (PEMFCs) application.