Reduced Graphene Oxide Hybrid Research Articles

Rational synthesis of reduced graphene oxide hybrid nanocomposite with iron tungstate for selective detection of epinephrine in biological fluids

Hybrid nanocomposites made from metal tungstate and stacked graphene nanosheets have attracted the curiosity of researchers due to their high conductivity, strong electrochemical activity, and quick electrochemical transfer response. These properties prompted us to employ co-precipitation and sonochemical approaches to create low-cost iron tungstate (FeWO4)/reduced graphene oxide (rGO) hybrid material. The as-synthesized FeWO4/rGO nanocomposites (NCs) were evaluated for their physicochemical properties and structural and morphological aspects. A modified electrode composed of FeWO4/rGO NCs was utilized to detect epinephrine (Eph), a significant neurotransmitter and hormone associated with various human activities. The electrochemical behavior of Eph was quantified using cyclic voltammetry, and differential pulse voltammetry (DPV) on a FeWO4/rGO NCs modified electrode. According to the DPV study, Eph concentration was linearly distributed from 0.05 to 990.5 µM. For determining Eph, the sensor had a detection limit of 0.0073 µM and a sensitivity of 5.857 µAµM−1 cm−2. The sensor displayed excellent recovery results for the determination of Eph in the human urine and epinephrine pills real samples, revealing its excellent practicality.

Three-Dimensional Reduced Graphene Oxide Hybrid Nano-Silver Scaffolds with High Antibacterial Properties.

In recent years, hazardous wastewater treatment has been a complex and global problem. In this work, by considering the antimicrobial activity of Ag nanoparticles (AgNPs) and reduced graphene oxide (rGO), we constructed an antibacterial device (G-AgNP) with AgNPs conformably deposited onto a 3D scaffold of reduced graphene oxide in situ. The major limitation, which is difficult to recycle, of two-dimensional graphene-silver composite materials in previous studies is improved. Characterization techniques, SEM, TEM, XRD, and XPS, confirmed the synthesis of nanocomposites. Attributed to its larger specific area, more active sites, and synergistic enhancement, the G-AgNP device demonstrated the best bacterial removal capacity, with an antibacterial rate for both E. coli and S. aureus as high as 100% at quite low AgNP contents. The reported G-AgNP has potential application as a wearable sewage treatment device and for the protection of wearable sensors as a promising sterilizing candidate based on its high and stable antibacterial efficiency.

Anisotropic microcellular epoxy/rGO-SCF aerogel foam with excellent compressibility and superior electromagnetic interference shielding performance

Carbon aerogel shows great potential in electromagnetic interference shielding (EMI) application and is generally strengthened by epoxy impregnation for harsh working environment. However, it is still challenging to simultaneously achieve high mechanical robustness and EMI performance, especially taking low-cost and light-weight feature into account. In this work, a “gelation-press drying-impregnation & micro-foaming” method was systematically reported to target microcellular epoxy foam containing hybrid reduced graphene oxide (rGO)/short-carbon-fiber (SCF) aerogel. Herein, aerogel morphology was transformed from isotropic honey-comb structure into anisotropic corrugated structure by controllable press air-drying. A further supercritical carbon dioxide (scCO2) foaming process was implemented for density reduction. Moreover, the anisotropic microcellular epoxy(m-EP)/rGO-SCF foam (D = ∼0.48 μm, Nf = 5.02 × 1012 cell/cm3) shows low density (1.14 g/cm3), high electrical conductivity (2365.0 S/m), enhanced compressibility (σb = 243.0 MPa, εb = ∼45%) and outstanding EMI shielding effectiveness (95.5 dB) with a low thickness (2.0 mm) within X band (8.2–12.4 GHz). Therefore, our work provides a universal step-by-step and industrial-friendly approach to fabricate light-weight carbon-aerogel-based foams with anisotropic carbon structure and outstanding EMI performance.

CuCo2S4@B,N-Doped Reduced Graphene Oxide Hybrid as a Bifunctional Electrocatalyst for Oxygen Reduction and Evolution Reactions.

In this report, a facile synthetic route is adopted for typically designing a hybrid electrocatalyst containing boron, nitrogen dual-doped reduced graphene oxide (B,N-rGO) and thiospinel CuCo2S4 (CuCo2S4@B,N-rGO). The electrocatalytic activity of the hybrid catalyst is tested with respect to oxygen evolution (OER) and oxygen reduction (ORR) reactions in alkali. Physicochemical characterizations confirm the unique formation of a reduced graphene oxide–non-noble-metal sulfide hybrid. Electrochemical evaluation by cyclic voltammetry (CV) and linear-sweep voltammetry (LSV) reveals that the CuCo2S4@B,N-rGO hybrid possesses enhanced ORR and OER activity compared to the B,N-rGO-free CuCo2S4 catalyst. The synthesized CuCo2S4@B,N-rGO hybrid demonstrates remarkable enhancement in catalytic performance with an improved onset potential (1.50 and 0.88 V) and low Tafel slope (112 and 73 mV dec–1) for both OER and ORR processes, respectively. In addition, the catalyst exhibits a diminutive potential difference (0.81 V) between the potential corresponding to the 10 mA cm–2 current density for OER and the half-wave potential for ORR. The superior catalytic activity and high durability of the hybrid material may be attributed to the synergistic effect arising from the metal sulfide and dual-doped reduced graphene oxide. The present study illuminates the possibility of using the dual-doped graphene oxide and metal sulfide hybrid as a competent bifunctional cathode catalyst for renewable energy application.

Conducting polymer-bridged three-dimensional heterojunctions of reduced graphene oxide/[formula omitted]-Fe2O3 hybrids for high-performance NO2 gas sensing

Three-dimensional (3D) reduced graphene oxide (RGO) networks show potentials for highly sensitive gas sensors. However, many insulating materials are usually used during RGO assembly process, which inevitably hinder the electron transfer efficiency, and affect the gas sensing performance. In this work, 3D structures based on nanospheres of conducting polymer layer-bridged γ-Fe2O3/RGO hybrids have been designed and demonstrated for NO2 sensing. Polyaniline (PANI), as a conducting polymer, can not only serve as self-assembly reagents to construct 3D hybrid structures, but also play an important role in participating electron transfer through forming p-n heterojunctions between interfaces of γ-Fe2O3 and RGO. The manufactured γ-Fe2O3@PANI@RGO sensors show a response as high as 911% when exposure to 50 ppm NO2, being over 124 times those of bare two-dimensional graphene sensors. In addition, excellent selectivity, stability, and low detectable concentration (100 ppb) to NO2 can be achieved for sensors based on this unique structure. It is​ suggested that the high performance can be ascribed to the formed 3D structures based on as-designed p-n heterojunctions and conjugation effect of PANI. The design strategy as well as constructed 3D RGO can provide a general route to fabricate high-performance gas sensors.

Platinum nanoparticles loaded carbon black: reduced graphene oxide hybrid platforms for label-free electrochemical DNA and oxidative DNA damage sensing

• Rapid and effective synthesis of platinum nanoparticles on the carbon black:reduced graphene oxide hybrids were achieved. • Facile and efficient electrode modification was performed with the hybrids. • Characterization of the surfaces proved homogeneous and robust distribution of the structures. • Sensitive fsDNA detection was accomplished with a low detection limit. • DNA damage and protection monitoring were carried out successfully. Carbon black-based hybrid materials have attracted great attention in the design of electrochemical sensors due to their consistent electroanalytical properties. With this in mind, for the first time, we present the preparation of platinum nanoparticles loaded carbon black:reduced graphene oxide (PtNPs/CB:rGO) hybrid platforms for label-free electrochemical DNA and DNA damage sensing. Synthesis of different hybrids was performed via microwave-assisted reduction method for the impregnation of platinum nanoparticles efficiently. These materials were characterized with X-ray diffraction analysis (XRD), Raman spectroscopy, transmission emission spectroscopy (TEM) and subsequently they were used for pencil graphite electrode modification in order to improve the characteristics of the surface. Modified electrodes were firstly applied for fish sperm DNA (fsDNA) analysis. The effect of different ratios (wt.:wt. %) of CB and rGO was investigated and it was shown that the hybrid material with 50:50 ratio had better sensitivity with a low detection limit of 0.14 mg L −1 and a good linearity to fsDNA between 1 and 200 mg L −1 (n = 3) based on guanine (G) oxidation by using differential pulse voltammetry (DPV). In order to expand this comparison, PtNPs/CB and PtNPs/rGO modified electrodes were also incorporated. Furthermore, the electroanalytical response of the hybrid material modified electrode was investigated based on the oxidation of thymine (T). Later on, oxidative DNA damage detection in the presence of Cu(II)/H 2 O 2 reagents and protection studies in the presence of ascorbic acid were performed successfully by using electrochemical impedance spectroscopy (EIS). The study pointed out the remarkable reproducibility and sensitivity of the CB-based modification for nanoparticle decoration.

Low‐Power Photodetectors Based on PVA‐Modified Reduced Graphene Oxide Hybrid Solutions

Photodetectors based on reduced graphene oxide (rGO) have attracted much attention owing to their simple and low-cost fabrication process. However, the aggregation and defects of rGO flakes still limit the performance of rGO photodetectors. Controlling the composition of rGO has become a vital factor for its prospective applications. For example, the interconnection between rGO and polymers for modified morphologies of rGO films leads to an enhanced performance of devices. In this work, a practical approach to engineer surface uniformity and enhance the performance of a photodetector by modifying the rGO film with hydrophilic polymers poly(vinyl alcohol) (PVA) is reported. Compared with the rGO photodetector, the on/off ratio for the PVA/rGO photodetector shows 3.5 times improvement, and the detectivity shows 53% enhancement even when the photodetector is operated at a low bias of 0.3V. This study provides an effective route to realize PVA/rGO photodetectors with a low-power operation which shows promising opportunities for the future development of green systems.

In Situ-Fabricated In2S3-Reduced Graphene Oxide Nanosheet Composites for Enhanced CO2 Electroreduction to Formate

The use of renewable electricity to catalyze carbon dioxide reduction is a promising method for CO2 utilization. However, the lack of highly efficient catalysts for CO2 reduction seriously limits its industrial applications. As a prototype, an ultrathin indium sulfide nanosheet (In2S3 NS) was synthesized and fabricated in situ on reduced graphene oxide (RGO) to obtain an In2S3–RGO composite. Induced by the two-dimensional (2D) structure of graphene oxide, the thickness of the In2S3 NSs was reduced from 30.2 to 3.9 nm. Simultaneously, the (440) plane of In2S3 NSs was preferentially grown parallel to the graphene plane, which was proven to possess a higher selectivity in catalyzing CO2 electroreduction to formate than the (111) and (311) planes by density functional theory calculations. Attributed to the 2D structure and full exposure of the (440) planes, a large electrochemically active surface area and high density of optimum active sites were both realized on the In2S3–RGO hybrids, leading to 91% faradaic efficiency of formate at −1.2 V versus The reversible hydrogen electrode in 0.1 M KHCO3 is 3.5 times that of bulk In2S3 (26%). Our work provides an effective way to prepare 2D transition metal catalysts with controllable crystal face exposure for specific reactions.

Preparation of Silver Decorated Reduced Graphene Oxide Nanohybrid for Effective Photocatalytic Degradation of Indigo Carmine Dye

Background: Even though silver decorated reduced graphene oxide (Ag-rGO) shows maximum absorptivity in the UV region, most of the research on the degradation of dyes using Ag-rGO is in the visible region. Therefore the present work focused on the photocatalytic degradation of indigo carmine (IC) dye in the presence of Ag-rGO as a catalyst by UV light irradiation. Methods: In this context, silver-decorated reduced graphene oxide hybrid material was fabricated and explored its potential for the photocatalytic degradation of aqueous IC solution in the UV region. The decoration of Ag nanoparticles on the surface of the rGO nanosheets is evidenced by TEM analysis. The extent of mineralization of the dye was measured by estimating chemical oxygen demand (COD) values before and after irradiation. Results: The synthesized Ag-rGO binary composites displayed excellent photocatalytic activity in 2 Χ 10-5 M IC concentration and 5mg catalyst loading. The optical absorption spectrum of Ag-rGO showed that the energy band-gap was found to be 2.27 eV, which is significantly smaller compared to the band-gap of GO. 5 mg of Ag-rGO was found to be an optimum quantity for the effective degradation of IC dye. The degradation rate increases with the decrease in the concentration of the dye at alkaline pH conditions. The photocatalytic efficiency was 92% for the second time. Conclusion: The impact of the enhanced reactive species generation was consistent with higher photocatalytic dye degradation. The photocatalytic mechanism has been proposed and the hydroxyl radical was found to be the reactive species responsible for the degradation of dye. The feasibility of reusing the photocatalyst showed that the photocatalytic efficiency was very effective for the second time.

Three-dimensional nano assembly of nickel cobalt sulphide/polyaniline@polyoxometalate/reduced graphene oxide hybrid with superior lithium storage and electrocatalytic properties for hydrogen evolution reaction

Engineering hierarchical nanostructures with enhanced charge storage capacity and electrochemical activity are vital for the advancement of energy devices. Herein, a highly ordered mesoporous three-dimensional (3D) nano-assembly of Nickel Cobalt Sulphide/Polyaniline @Polyoxometalate/Reduced Graphene Oxide (NiCo2S4/PANI@POM/rGO) is prepared first time via a simple route of oxidative polymerization followed by a hydrothermal method. Morphological analysis of the resulting hybrid reveals the sheet-like structures containing a homogeneous assembly of PANI@POM and NiCo2S4 on the graphene exterior maintaining huge structural integrity, large surface area and electrochemically active centres. The electrochemical analysis of the nanohybrid as the anode of the lithium-ion battery (LIB) has delivered ultra-huge reversible capacity of 735.5 mA h g−1 (0.1 A g−1 after 200 cycles), superb capacity retention (0.161% decay/per cycle at 0.5 A g−1 for 1000 cycles), and significant rate capability (355.6 mA h g−1 at 2 A g−1). The hydrogen evolution reaction (HER) measurement also proves remarkable activity, extremely low overpotential and high durability. The extraordinary performance of the nanohybrid is due to the presence of abundant electroactive centres, high surface area and a large number of ion exchange channels. These outstanding results prove the advantages of a combination of NiCo2S4, graphene sheets, and PANI@POM in energy devices.

Highly anisotropic thermal conductivity and electrical insulation of nanofibrillated cellulose/Al2O3@rGO composite films: effect of the particle size

Nanofibrillated cellulose (NFC) film has received tremendous attention due to its excellent electrical insulation, which shows great application prospects in the field of electronic devices. However, the low efficient heat dissipation of NFC film largely limits its use in advanced applications. In this work, the reduced graphene oxide hybrid fillers loaded alumina (Al2O3) particles with different sizes were synthesized by different drying methods, and then they were mixed with NFC to prepare a series of NFC-based composite films. The effect of Al2O3 particle sizes on the thermal conductivity of NFC-based composite films was studied. The results showed that the surface areas of l-Al2O3 particles were smaller than that of s-Al2O3 particles, resulting in the smaller interface thermal resistance and superior thermal conductivity of the film containing l-Al2O3 particles. The NFC-based composite films showed great potential for applications in thermal management by adjusting the particle size of fillers.

Boosting room-temperature ppb-level NO2 sensing over reduced graphene oxide by co-decoration of α-Fe2O3 and SnO2 nanocrystals

As promising sensing materials, reduced graphene oxide (RGO)-based nanomaterials have drawn considerable attention in the fields of gas monitoring owing to their low operating temperature. However, constructing RGO-based room-temperature gas sensors possessing ppb-level limit of detection with high sensitivity remains challenging. In this work, a series of highly sensitive NO2 sensors were fabricated using α-Fe2O3 and SnO2 co-decorated RGO hybrids (designated as α-Fe2O3/SnO2-RGO) as sensing materials. They were rationally synthesized by a one-pot hydrothermal method. Compared to SnO2 modified RGO hybrids (SnO2-RGO with bandgap of 3.88 eV), the bandgap energy of α-Fe2O3/SnO2-RGO hybrids (3.53 eV) was reduced by adding α-Fe2O3; the narrower bandgap facilitated the sensing materials to release more electrons and form more oxygen ions at room temperature. Besides, the high carrier migration of RGO, which served as continuous phase, identical structure with ultrasmall particle size of α-Fe2O3 and SnO2 (about 3–6 nm), and abundant chemisorbed oxygen species on the surface (20.8%) of the sensing materials, as well as their suitable bandgap (3.53 eV) in the sensing materials, significantly improved NO2 response at room temperature. Among the sensors fabricated, α-Fe2O3/SnO2-RGO-15-based NO2 sensor had the highest response of 7.4 with a short response time of 59 s towards 1 ppm NO2; it could even reach a response of 2.6 towards 100 ppb NO2. Notably, α-Fe2O3/SnO2-RGO-15 sample has excellent capability to recognize NO2, where the response value (7.4) towards 1 ppm NO2 is about 7 times higher than that of 100 ppm ammonia and common volatile organic compounds (formaldehyde, toluene, ethanol and acetone). Such NO2 sensor has superior repeatability with negligible response deviation towards 1 ppm NO2 for four reversible cycles. This makes it to have a great potential application in the field of NO2 detection.

Investigations on the capacitive behaviour of hydrothermally synthesised cadmium meta niobate incorporated reduced graphene oxide hybrid nanocomposite electrode material

Investigations on the capacitive behaviour of hydrothermally synthesised cadmium meta niobate incorporated reduced graphene oxide hybrid nanocomposite electrode material

MOF-derived ruthenium-doped amorphous molybdenum dioxide hybrid for highly efficient hydrogen evolution reaction in alkaline media.

Ruthenium-doped amorphous molybdenum dioxide coupled with a reduced graphene oxide hybrid (Ru-MoO2@PC/rGO) is synthesized using polyoxometalate-based MOFs/GO as a precursor. Benefitting from the synergistic effect of numerous exposed active sites, Ru dopants and the introduction of GO, the designed catalyst shows exceptional electrocatalytic performance toward the HER in alkaline media.

Highly Stable Polyaniline Array@ Partially Reduced Graphene Oxide Hybrid Fiber for High-Performance Flexible Supercapacitors

Highly Stable Polyaniline Array@ Partially Reduced Graphene Oxide Hybrid Fiber for High-Performance Flexible Supercapacitors

Silver-doped ZnO embedded reduced graphene oxide hybrid nanostructured composites for superior photocatalytic hydrogen generation, dye degradation, nitrite sensing and antioxidant activities

Doped semiconductor metal oxide-rGO mediated photocatalysts have exhibited fascinating potentiality and utilized in a variety of applications. This could be attributed to their large surface area, unique morphologies and thickness-dependent characteristics. In this study, we focused on the green synthesis of ZnO, Ag-ZnO and Ag-ZnO-rGO nanocomposite using Cucumis melo fruit juice as fuel via solution combustion synthesis method. The synthesized materials were characterized thoroughly using PXRD, TEM, SEM, FTIR, UV-DRS, EDX and Raman spectroscopic techniques. As prepared materials were evaluated for photocatalytic H2 evolution by water splitting, dye degradation using visible light, photoluminescence, nitrite sensing and antioxidant activities. It was found that Ag-ZnO-rGO nanocomposite exhibited 3.2 and 1.7 times higher H2 evolution property than ZnO and Ag-ZnO nanoparticles respectively. Further, the composite material was found to be superior visible light active photocatalyst towards degradation of methylene blue (MB) dye compared to pure and Ag doped ZnO NPs. Photoluminescence studies revealed that Ag-ZnO-rGO nanocomposite showed remarkable reduction in the peak intensity of PL spectrum compared to ZnO and Ag-ZnO due to better charge separation. Ag-ZnO-rGO showed superior electrocatalytic performance towards the detection of NaNO2 and radical scavenging activity by inhibiting the activity of DPPH compared to ZnO and Ag-ZnO NPs. The superior activities of Ag-ZnO-rGO is probably due to lowering of bandgap by rGO, crystal lattice incorporated and ZnO-rGO interface accumulated Ag and also possibly due to the ability of rGO to facilitate the electron transport that suppress the recombination rate of photogenerated charge carriers. This study gives a concise methodology for the development of visible light responsive photocatalyst for various applications such as H2 evolution, dye degradation, photoluminescence and electrocatalytic nitrite sensing & antioxidant activities.

Construction and investigation on perovskite-type SrTiO3@ reduced graphene oxide hybrid nanocomposite for enhanced photocatalytic performance

To construct rGO/SrTiO 3 nanocomposite using a facile hydrothermal synthetic approach for enhanced photocatalytic application. In this study, the structural, morphological, elemental, surface compositional, optical properties, and photocatalytic activity of rGO/SrTiO 3 nanocomposites were investigated. From the various analyses, the synthesized nanocomposites produce heterostructure formation between reduced graphene oxide (rGO) and SrTiO 3 . By the optical analysis, the results showed that prepared ESG 10 photocatalyst has efficient charge separation and migration with suppressed recombination probability of photogenic charge carriers. The photocatalytic reactivity of the synthesised photocatalysts was evaluated by methylene blue (MB) aqueous dye and 2-nitrophenol (2-NP) degradation under UV-Visible (UV-Vis.) light irradiation. Therefore, the ESG 10 photocatalyst exhibited a maximum removal efficiency of 91% and 81% over MB dye and 2-NP, respectively. In contrast to other samples, the introduction of rGO could suggestively enhance the photocatalytic activity by increasing the amount of rGO, and the degradation rate was also reduced after the optimal level of rGO. The radicals involved in the degradation process are investigated by scavenger experiments. The recycle experiment reveals that the ESG 10 photocatalyst does not show any major loss of activity after 4 consecutive runs. Meanwhile, the possible reaction mechanism and interface characteristics are also discussed. • The perovskite rGO/SrTiO 3 nanocomposite was prepared via facile hydrothermal route. • rGO possess interfacial contact with E SRT provides more charge transport ability. • ESG 10 photocatalyst achieves 91% of MB dye degradation efficiency. • Possible degradation mechanism and charge transfer pathways were discussed. • The ESG 10 photocatalyst was utilized for 4 recycle runs with good stability.

In-Situ Synthesis of Fe2O3 Nanospheres/Co3O4 Nanowires-Connected Reduced Graphene Oxide Hybrid Networks for High-Performance Energy Storage Device

Three–dimensional (3D) hybrid networks consisted of reduced graphene oxide (rGO) sheets interconnected by Co3O4 nanowires (rGO/Co3O4), followed by decoration of Fe2O3 nanospheres (NSs) , were demonstrated by a facile hydrothermal method, with which the rGO/Co3O4 networks were acted as nucleation sites for the in-situ synthesis of Fe2O3 NSs. The intimate contacts between rGO, Co3O4 NWs and Fe2O3 NSs resulting in an excellent conductive behavior and unique structure. Hence, the rGO/Co3O4@Fe2O3 hybrid networks exhibit a high capacity of 243.1 mAh·g–1 at the current density of 1 A·g–1. Figure 1

Supercapacitor properties of V10O14(OH)2 and reduced graphene oxide hybrids: Experimental and theoretical insights

In this work, V10O14(OH)2 nanostructure and its hybrid with reduced graphene oxide (rGO/V10O14(OH)2) have been synthesized by a simple hydrothermal process, and the supercapacitance property has been explored. The material's crystal structure, surface morphology, elemental compositions, and oxidation state of metal atoms are properly characterized. The structure and electronic properties of V10O14(OH)2 and rGO/V10O14(OH)2 are presented using Density Functional Theory (DFT) investigations. Using the cyclic voltammetry (CV) technique, the capacitance of the rGO/V10O14(OH)2 hybrid was found to be 558 Fg−1 at a scan rate of 1 mV/s, which is 2.9 times greater than the capacitance of the V10O14(OH)2 material. The hybrid material provides 94% operational stability over 5000 cycles. From the Trassatti plot, the capacitance contribution of rGO/V10O14(OH)2 and V10O14(OH)2 are estimated, and found that the maximum capacitance contribution is due to diffusion-controlled pseudocapacitance phenomena, i.e., 87.5% and 95.9%, respectively. Enhanced electronic states near Fermi level and improved quantum capacitance for the hybrid structure justify the superior charge storage performance of the integrated structure (rGO/ V10O14(OH)2) as observed in the experiment. Also, the mobility of the electrolyte ions increases in the hybrid structure due to lower diffusion energy barrier leading to better charge transfer kinetics.

Green Synthesis of Cu Nanoparticles in Modulating the Reactivity of Amine-Functionalized Composite Materials towards Cross-Coupling Reactions.

Control over both dispersion and the particle size distribution of supported metal particles is of paramount importance for the catalytic activity of composite materials. We describe the synthesis of materials with Cu nanoparticles well-dispersed on different amine-functionalized supports, using the extract of Wallich Spurge as a green, reducing agent. Graphene oxide (GO), mesoporous silica (MCM-41), mesoporous zirconia, and reduced graphene oxide-mesoporous silica (RGO-MCM-41) were explored as supports. Cu nanoparticles were better stabilized on RGO-MCM-41 compared to other supports. The novel composite materials were characterized by X-ray diffraction (XRD), Raman spectra, Scanning electron microscope (SEM), Transmission electron microscopy analysis and HR-TEM. SEM and EDX techniques. High angle XRD confirmed the conversion of graphene oxide to reduced graphene oxide (RGO) with plant extract as a reducing agent. Both XRD and TEM techniques confirmed the Cu nanoparticle formation. The catalytic activity of all the prepared materials for the Ullmann coupling reactions of carbon-, oxygen-, and nitrogen-containing nucleophiles with iodobenzene was evaluated. From the results, 5 wt% Cu on amine-functionalized reduced graphene oxide/mesoporous silica nanocomposite (5 wt%Cu(0)-AAPTMS@RGO-MCM-41) exhibited excellent efficiency with 97% yield of the C-C coupling product in water at 80 °C in 5 h. The activity remained unaltered almost up to the fourth cycle. The Cu nanoparticles stabilized by organic amine group on RGO hybrid facilitated sustained activity.