Reduced Graphene Oxide Nanohybrid Research Articles

Silver Nanoparticles Decorated in In Situ Reduced Graphene Oxide Nanohybrids Improved Properties in Poly(vinylidene fluoride)/Poly(methyl methacrylate) Blends

In this paper, reduced graphene oxide decorated with silver nanoparticle (rGO-Ag) nanohybrids were prepared using an environmentally friendly approach and incorporated as reinforcement in poly(vinylidene fluoride)-poly(methyl methacrylate) blends via a melt mixing process. The microstructure of rGO-Ag nanohybrids and its effect on the microstructure, mechanical, thermal, and electrical properties of the PVDF/PMM/rGO-Ag was studied using Fourier transform infrared (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile, thermogravimetric analysis (TGA), and impedance spectroscopy methods. FTIR and TEM analysis confirmed that rGO-Ag successfully synthesized and Ag nanoparticles are located on the rGO surface. The tensile analysis demonstrated that incorporating 1 wt.% of rGO-Ag in PVDF/PMMA blend increases Young’s modulus and strength of nanocomposite up to 31% and 35%, respectively. The Halpin-Tsai model was also used for PVDF/PMMA/rGO-Ag nanocomposites, and the results confirmed that this model works well to predict the tensile modulus. Impedance spectroscopy analysis showed that the presence of rGO-Ag nanohybrids in PVDF/PMMA blend effectively enhanced the conductivity of PVDF/PMMA blend. TGA results demonstrated that the presence of rGO-Ag nanohybrids enhanced the thermal stability of nanocomposites and increased the degradation temperature of PVDF/PMMA/rGO-Ag nanocomposites in the range of 20°C compared to PVDF/PMMA blend.

Development of silver oxide-loaded reduced graphene oxide nanohybrids for enhanced photocatalytic activity under visible light in aqueous solutions

We report on the synthesis of silver oxide/reduced graphene oxide nanocomposites (Ag/rGO NCs) using a hydrothermal technique. This paper presents a simple method for synthesizing Ag/rGO hybrid nanocomposites, which can be used for environmentally treating hazardous organic pollutants. The photocatalytic degradation of model artificial Rhodamine B dye and bisphenol A was assessed under visible light illumination. The crystallinity, binding energy, and surface morphologies of the synthesized samples were determined. The silver oxide loading sample resulted in a decrease in the rGO crystallite size. SEM and TEM images demonstrate strong adhesion of the Ag NPs to the rGO sheets. XPS analysis validated the binding energy and elemental composition of the Ag/rGO hybrid nanocomposites. The objective of the experiment was to enhance the photocatalytic efficiency of rGO in the visible region using Ag nanoparticles. The synthesized nanocomposites in the visible region exhibited good photodegradation percentages of approximately 97.5% and 98.6% after 120 min of irradiation for pure rGO, Ag NPs, and Ag/rGO nanohybrid, respectively. Furthermore, the Ag/rGO nanohybrid maintained their degradation ability for up to three cycles. The synthesized Ag/rGO nanohybrid demonstrated enhanced photocatalytic activity, expanding their potential for environmental remediation. Based on the investigations, Ag/rGO nanohybrid proved to be an effective photocatalyst and holds promise as an ideal material for future applications in preventing water pollution.

A crosslinked coral-like Co@CoO/RGO nanohybrid structure with good electromagnetic wave absorption performance

The combination of magnetic and dielectric materials followed by appropriate structure design is an effective approach to achieve high electromagnetic wave absorption properties. Here, crosslinked Co@CoO/reduced graphene oxide nanohybrids (CCRGO) were fabricated via a simple three-step method. The experimental results show that compared with previous works, the as-prepared CCRGO nanohybrids achieve higher electromagnetic wave absorption and broader effective bandwidth at a lower filler loading. The electromagnetic parameters and electromagnetic wave absorption performance could be apparently adjusted by controlling the adding content of graphene oxide (GO) and the reduction temperature. Among a series of samples, CCRGO3-650 nanohybrid yields the best electromagnetic wave absorption performance benefiting from the proper GO addition and reduction temperature. At a filler loading of 20 wt%, the maximal reflection loss reaches to −64.67 dB at a thickness of 2.53 mm and the effective bandwidth below −10 dB covers the whole X band at a thickness of 2.51 mm. The good performance may be ascribed to the advantages of the dielectric and magnetic component as well as the special crosslinked structure, which triggers a synergistic absorption mechanism including multiple reflection/scattering, interface polarization, dipole polarization, conductive loss, eddy current loss, exchange resonance in the electromagnetic wave dissipation process. The good electromagnetic wave absorption performance affirms the potential application of CCRGO nanohybrids in the field of stealth materials.

Synthesis of NiO-Doped ZnO Nanoparticle-Decorated Reduced Graphene Oxide Nanohybrid for Highly Sensitive and Selective Electrochemical Sensing of Bisphenol A in Aqueous Samples

Synthesis of NiO-Doped ZnO Nanoparticle-Decorated Reduced Graphene Oxide Nanohybrid for Highly Sensitive and Selective Electrochemical Sensing of Bisphenol A in Aqueous Samples

Facile Hydrothermal Fabrication of an α-Ni(OH)2/N-Doped Reduced Graphene Oxide Nanohybrid as a High-Performance Anode Material for Lithium-Ion Batteries

Metal hydroxides are a kind of promising anode materials for lithium-ion batteries (LIBs) because of their large theoretical capacity, easy preparation, and low cost. However, their application has been restricted by cycling instability and slow kinetics arising from large volume variation and poor conductivity. Herein, a nanostructured α-Ni(OH)2/N-doped reduced graphene oxide (NrGO) hybrid is fabricated through a hydrothermal approach. This Ni(OH)2/NrGO hybrid exhibits high reversible capacity (1220 mA h g–1 at 0.2 A g–1), superior cyclability, and superb rate ability (559 mA h g–1 at 10 A g–1). The excellent electrochemical performance benefits from the hybrid nanostructure, which inhibits the agglomeration of active nanoparticles, exposes more electroactive sites, inhibits the restacking of NrGO sheets, and retains mechanical integrity during cycling. Besides, the highly conductive NrGO sheets provide efficient transport pathways for electrons and further enhance the electrochemical kinetics. When paired with the LiCoO2 cathode, this Ni(OH)2/NrGO hybrid displays a stable capacity in a full cell, demonstrating its promising practicability in LIBs.

A Novel Strategy for Remediation of Heavy Metal Removal and Oil/Water Separation from Carbon-Based Nanohybrid

Increasing the world population results in the consequent consumption of primary resources, which produces high amounts of waste. The increasing amount of waste has negatively impacted the environment and ecosystem. The growing population demands a high amount of food resources, which increases anthropogenic activities. So, Environmental pollution has become a severe problem due to this anthropogenic activity affecting our planet. This problem cannot be neglected and has become the most challenging task of the 21st century. Researchers are putting effort into developing new nanohybrid, which should be environmentally friendly, with greener methods of synthesis to overcome and remediate the environment from pollutants. Scientists are trying to move towards nanotechnologies and nanomaterials to resolve the upcoming challenges related to environmental pollutants. This article describes heavy metal pollutants, recovery of oil from wastewater, etc. This article will also focus on the carbon-based nanohybrid, which can be used for the environmental recovery strategies of polluted areas. In particular, this article will give more attention towards the recent method developed and method to capturing heavy metal using silver fabricated reduced graphene oxide nanohybrid for the application of heavy metal capture and separation of oil water.

Hierarchical flower-like MoS2/reduced graphene oxide nanohybrids supported on nickel foam as a high-performance electrode material for supercapacitor applications

Flower-like MoS2/rGO nanohybrids have been synthesized using one-pot hydrothermal reaction method. The supercapacitor cell exhibited excellent electrochemical performance predominated by surface capacitive processes.

Anti-bacterial and arsenic remediation insights in aqueous systems onto heterogeneous metal oxide (Cu0.52Al0.1Fe0.47O4)/rGO hybrid: an approach towards airborne microbial degradation.

Copper-based ternary metal oxide (i.e., Cu0.52Al0.01Fe0.47O4) impregnated reduced graphene oxide nanohybrid is verified for microbial and arsenic treatment. Growth inhibition of colonies are observed around 99.99% (E. coli), and 99.83% (S. aureus) at 10-20μg/mL of hybrid dosage, respectively. The inhibition rates for both the colonies are increased to 99.9998% at 80μg/mL. TEM images have shown insight of cell-content/lipid leakage behavior after inoculating with the hybrid. The efficient hindrance towards microbial colony growth is attributed to better charge transfer, reactive oxygen species generation, and metal-ion release. Maximum arsenic sorption capacities are observed around 248 and 314mg/g for As(III), and As(V), respectively (Ci ~ 500ppm). Surface morphology studies onto arsenic adsorption are reported with atomic force microscope, and FT-IR/Raman analysis. A detailed discussion onto individual spectra of As 3d spectra confirmed the occurrence of redox transformation in arsenic species [As(III)]. The variation in the quantity (at. %) of oxygen functional groups in O1s spectra (i.e., M-O, M-OH, and -OH2) onto the hybrid supported the ligand-exchange behavior. Cyclic voltammetry study in arsenic electrolytes (10µM - 1mM) provides the occurrence of various in-situ electrochemical reactions supporting the redox activity. A significant electromagnetic wave absorption characteristics of the present hybrid is proposed with plausible airborne antimicrobial-agent abilities.

Hydrothermal production of low-cost CeNi2S4-reduced graphene oxide composites as an efficient counter electrode for high performance dye-sensitized solar cells

Dye sensitized solar cell (DSSC) technology could become a low-cost solution for solar energy harvesting if the use of expensive dyes and Pt can be avoided. This work reports the development of a novel nanohybrid based on CeNi2S4 nanotubes embedded on sheets of reduced graphene oxide (RGO), which can serve as excellent counter electrode for DSSC showing great promise to replace Pt. The structural and morphological characterization of the nanocomposite synthesized using a simple one step hydrothermal method revealed well defined crystalline nanotubes of CeNi2S4 (with length 190 nm and diameter 8.54 nm) uniformly embedded on the surfaces of the RGO sheets (∼2.65 μm in size). The morphology and size of the nanotubes were found to be dependent on the duration of the hydrothermal reaction. The optimized CeNi2S4/RGO nanohybrid CE when used as counter electrode in DSSC, photo conversion efficiency as high as 9.21 ± 0.03 % was recorded, a value almost equal to that obtained from the DSSC fabricated with Pt as counter electrode and much higher than that with bare CeNi2S4 justifying its potential use in Pt-free DSSC. The improved performance of the electrode have been attributed to the hierarchical nanohybrid structure consisting of catalytically active 1D CeNi2S4 nanotubes embedded on electrically conducting 2D RGO sheets that provides fast ion diffusion pathways, large accessible surface area and good chemical and thermal stability.

Raman, TEM, EELS, and Magnetic Studies of a Magnetically Reduced Graphene Oxide Nanohybrid following Exposure to Daphnia magna Biomarkers.

A ternary nanocomposite made of nanomaghemite, nanoanatase, and graphene oxide has been successfully synthesized using an inorganic coprecipitation approach, and it has been systematically investigated by X-ray diffraction, transmission electron microscopy, and different spectrocopic techniques (electron energy loss, µ-Raman, and 57Fe Mössbauer) after interaction with an effluent containing Daphnia magna individuals. Specifically, the influence of the nanocomposite over the Daphnia magna carapace, administered in two doses (0.5 mg mL−1 and 1 mg mL−1), has been characterized using µ-Raman spectroscopy before and after laser burning protocols, producing information about the physicochemical interaction with the biomarker. The thermal stability of the nanocomposite was found to be equal to 500 °C, where the nanoanatase and the nanomaghemite phases have respectively conserved their structural identities. The magnetic properties of the nanomaghemite have also been kept unchanged even after the high-temperature experiments and exposure to Daphnia magna. In particular, the size, texture, and structural and morphological properties of the ternary nanocomposite have not shown any significant physicochemical modifications after magnetic decantation recuperation. A significant result is that the graphene oxide reduction was kept even after the ecotoxicological assays. These sets of observations are based on the fact that while the UV-Vis spectrum has confirmed the graphene oxide reduction with a localized peak at 260 nm, the 300-K and 15-K 57Fe Mössbauer spectra have only revealed the presence of stoichiometric maghemite, i.e., the two well-defined static magnetic sextets often found in the bulk ferrimagnetic counterpart phase. The Mössbauer results have also agreed with the trivalent-like valence state of Fe ions, as also suggested by electron energy loss spectroscopy data. Thus, the ternary nanocomposite does not substantially affect the Daphnia magna, and it can be easily recovered using an ordinary magnetic decantation protocol due to the ferrimagnetic-like character of the nanomaghemite phase. Consequently, it shows remarkable physicochemical properties for further reuse, such as cleaning by polluted effluents, at least where Daphnia magna species are present.

Direct acidic graphene oxide enabled fabrication of three-dimensional molybdenum trisulfide and reduced graphene oxide nanohybrid aerogels with simultaneous energy storage and electrocatalytic capability

To confront the ever-growing energy and environmental concerns, the rational design and development of newer yet high-performance energy storage and conversion materials are highly desirable. Herein, we proposed a scalable and simplistic approach to prepare a three-dimensional (3D) MoS3/reduced graphene oxide (RGO) aerogel as an efficient electroactive material. Under a benign in-situ hydrothermal method, an acidic graphene oxide was directly used as support and catalyst to form uniformly dispersed MoS3 nanoparticles within porous 3D RGO architecture. Owing to its unique synergy of plentiful exposed active sites and highly porous conductive network, the resulting nanohybrid was successfully used as a supercapacitor electrode and electrocatalyst for hydrogen evolution reaction (HER). The as-obtained 3D MoS3/RGO nanohybrid-based electrode provides a higher specific capacitance of 576.5 F·g−1, more significant than the pristine MoS3 electrode (206.4 F g−1). Likewise, an asymmetric supercapacitor (ASC) device assembled using the MoS3/RGO and activated carbon (AC) delivers a maximum energy density of 35.2 Wh kg−1 at a power density of 528 W kg−1, over a voltage window of 1.5 V. Moreover, remarkable cycling stability accompanied by 92% capacitance retention was also observed. Similarly, the resulting 3D MoS3/RGO nanohybrids display significant HER activity, requiring a smaller overpotential of only 0.121 V to accomplish a current density of 10 mA·g−1 in conjunction with a smaller Tafel slope value of 60 mV dec−1 in 0.5 M H2SO4. Such remarkable electrocatalytic activity is accredited to its unique porous nanoarchitecture, sulfur-rich active centers, and improved conductivity. Overall, the implemented optimal methodology offers technological scalability in the fabrication of low-cost 3D nanohybrids electrodes composed of graphene and TMDs for various energy-related applications.

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.

An Electrochemical Sensor for Quantitation of the Oral Health Care Agent Chlorogenic Acid Based on Bimetallic Nanowires with Functionalized Reduced Graphene Oxide Nanohybrids.

Chlorogenic acid (CGA), a phenolic acid from coffee, has been regarded as a powerful ingredient against oxidative stress and inflammation. Meanwhile, its healing feature to interfere with periodontal disease (PD) makes it a promising drug candidate. However, the existing methods for chlorogenic acid detection limit its practical application in purification and further pharmacological study in stomatology due to their lack of accuracy and productivity. Therefore, it is crucial to find a forceful approach to precisely evaluate CGA for an in-depth anti-PD study. In this work, we reported a facile and controllable synthesis of Pt@Pd nanowires (NWs) in a non-compacted core–shell structure with high electrocatalytic activity. In addition, polyethylenimine (PEI)-capped reduced graphene oxide (rGO) nanoflakes provided large binding sites for a network structure composed of interweaved Pt@Pd nanowires and protected hemin from self-destruction, which empowered Pt@Pd NWs-Hemin-PEI-rGO nanohybrids to own a large electroactive surface area and great electrochemical property for CGA detection. The enzyme-free electrochemical sensor based on Pt@Pd NWs-Hemin-PEI-rGO displayed a favorable capacity for trace CGA detection with a detection limit of 7.8 nM and a wide linear range of 0.5 μM to 4 mM. The exceptional sensitivity and selectivity of the sensor made it accomplish the measurements of chlorogenic acid in soft drinks and coffee with high consistency of HPLC results. The satisfactory performance of the obtained sensor enables it to be used for quality control and study of drug metabolism in PD treatments.

Fabrication of a polyoxotungstate/metal-organic framework/phosphorus-doped reduced graphene oxide nanohybrid modified glassy carbon electrode by electrochemical reduction and its electrochemical properties.

Hybrid nanocomposites based on polyoxometalates (POMs), metal–organic frameworks (MOFs), and graphene oxide (GO) have a unique set of properties. They have specific properties such as high acidity, oxygen-rich surface, and good redox capability from POMs. In contrast, they do not have weaknesses of POMs such as a low surface area, and high solubility in aqueous media. Herein, a novel organic–inorganic nanohybrid compound based on H3PW12O40 (PW12), a Co-based MOF, and GO was prepared. The prepared hybrid nanocomposite (PW12/MOF/GO) was characterized using different techniques. Then, a PW12/MOF/GO nanocomposite modified glassy carbon electrode (GCE) was fabricated by the drop-casting method and next was dried at room temperature. Then, the PW12/MOF/GO/GCE was subjected to electrochemical reduction at a constant potential of −1.5 V, in 0.1 M H3PO4 solution containing 0.10% w/v PW12/MOF/GO additive. The morphology, electrochemical activity, and stability of the modified electrode (PW12/MOF/P@ERGO/GCE) were studied with FE-SEM coupled with EDS, CV, and amperometry. The obtained results confirmed that the PW12/MOF/P@ERGO/GCE could be effective in hydrogen evolution reaction (HER). The electrochemical activity of the PW12/MOF/P@ERGO/GCE due to the desirable microstructure of the electrocatalyst (e.g. high active surface area and homogeneous distribution of the PW12/MOF/P@ERGO), and also the synergistic effect of the blocks, is more than those of PW12/GCE, MOF/GCE, PW12/MOF/GCE, and P@ERGO/GCE. Moreover, the PW12/MOF/P@ERGO/GCE showed an excellent long-term stability under the air atmosphere.

Multifunctional hybrid UF membrane from poly(ether sulfone) and quaternized polydopamine anchored reduced graphene oxide nanohybrid for water treatment

In this study, a new quaternized polydopamine anchored reduced graphene oxide (QSiPD-rGO) nanohybrid was prepared through a one-step mussel-inspired tailoring of GO using a quaternized silica precursor and dopamine. The QSiPD-rGO was applied for the first time as a nanofiller, at a significant loading rate of up to 8 wt%, to manufacture positively charged, high flux, fouling resistant and antibacterial hybrid poly(ether sulfone) (PES) ultrafiltration (UF) membranes, via non-solvent induced phase separation. A suite of tools was utilized to thoroughly characterize the nanohybrid and the membranes, including SEM-EDX, Raman, ATR-FTIR, TGA, AFM, zeta potential and contact angle measurements. The surface morphology, charge and hydrophilicity of the membranes were tuned upon integrating the nanohybrid. Consequently, pure water flux significantly increased, reaching ~ 270 L m−2 h−1 (at 1 bar) for PMQ4 with 6 wt% QSiPD-rGO loading. This was 94% higher than the corresponding flux of pristine membrane (139 L m−2 h−1, at 1 bar). The hybrid membranes also showed superior fouling resistance during the UF of 500 ppm bovine serum albumin (BSA) solution. The BSA rejection rate of the hybrid membranes was very high and uncompromised by their high flux, exceeding 98% for PMQ4. Additionally, a remarkable antibacterial activity (against E. Coli.) of the membranes was induced by the nanohybrid, with a strong correlation between this activity and QSiPD-rGO loading.

Improving graphene gas sensors via a synergistic effect of top nanocatalysts and bottom cellulose assembled using a modified filtration technique

Improving graphene properties with nanosized catalysts is of interest for numerous applications, especially chemical sensors. Thus, the aim of this study is to prepare nanocatalysts and assemble them on reduced graphene oxide (RGO) for sensing nitric oxides (NOx). The nanocatalysts used in this study include TiO2 nanoparticles (commercial) with WO3, WS2, and MoS2 nanoflakes (mechanically synthesized). Their decoration on the RGO active channel (forming nanohybrids) was obtained via a modified vacuum filtration technique, in which a small syringe and USB-powered pump were employed to surmount the limitation of the conventional filtration setup in the patternable fabrication of device arrays. Sensing measurements expose a co-effect of the nanocatalysts and the cellulose substrate on our RGO-based paper sensors. That can boost the sensitivity of RGO toward NO (1-10 ppm) and NO2 (0.7–3.5 ppm) but weaken it toward NH3 (2–20 ppm). Particularly among the nanocatalysts, MoS2 nanoflakes made our RGO nanohybrid possessing the fastest response/recovery and the highest selectivity toward NOx at room temperature (25 °C). Generally, this study reveals the synergistic effect of MoS2 and cellulose substrate on the improvement of RGO sensing ability and confirms the aptitude of our sensors for flexible and disposable NOx sensing applications.

Ivermectin detection using Ag@ B, S co-doped reduced graphene oxide nanohybrid

Silver nanoparticles (AgNPs) modified boron and sulfur co-doped reduced graphene oxide (B, S@rGO) were prepared by one-pot hydrothermal method for the first time. The combination between AgNPs and B, S@rGO decreases stacking of B, S@rGO and decreases the particle size of AgNPs; in addition, it enhances the effective surface area and electro-catalytic activities of the nanocomposite. The morphology and structure of AgNPs/B, S@rGO were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron microscope (XPS), Raman spectroscopy, UV-Vis spectroscopy, thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET). The electro-catalytic activity of AgNPs/B, S@rGO was studied using cyclic voltammetry (CV), electron impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Because of the synergetic effects of AgNPs and B, S@rGO, the modified electrode displayed considerably enhanced sensitivity to ivermectin (IVM) determination. The voltammetric response is linear over the range of 0.3–60.0 nM with LOD (S/N = 3) of 0.1 nM. The proposed sensor exhibited good selectivity, reproducibility, and long-term stability. The modified electrode was used to analyze IVM in injections, urine, and tap-water with recoveries % of 99.6–105.8% and RSDs of 2.14–3.65%.

One-Step Solvothermal Route to Sn4P3-Reduced Graphene Oxide Nanohybrids as Cycle-Stable Anode Materials for Sodium-Ion Batteries.

Sn4P3, owing to its high theoretical volumetric capacity, good electrical conductivity, and relatively appropriate potential plateau, has been recognized as an ideal anode for sodium-ion batteries (NIBs). However, the current synthetic routes for Sn4P3-based nanohybrids typically involve foreign-template-based multistep procedures, limiting their large-scale production and applications in NIBs. Using commercial red phosphorus as the phosphorus source and nontoxic ethanolamine as the solvent, we herein report a facile and scalable solvothermal protocol for the one-step preparation of Sn4P3-reduced oxide graphene (denoted as Sn4P3-rGO) hybrid materials. Benefiting from the novel strategy and elaborate design, ultrasmall Sn4P3 nanoparticles (2.7 nm on average) are homogeneously anchored onto rGO. The high conductivity of the rGO network and the short electron/ion diffusion path of ultrasmall Sn4P3 nanoparticles give the Sn4P3-rGO hybrid high capacities and stable long-term cyclability. Specifically, the optimized Sn4P3-rGO hybrid displays a remarkable reversible capacity of 663.5 mA h g-1 at a current density of 200 mA g-1, ultralong-term cycle life (301 mA h g-1 after 2500 cycles at a high current density of 2000 mA g-1), and excellent rate capability, presenting itself as a highly promising anode material for NIBs.

Highly sensitive electrochemical detection of cancer biomarker based on anti-EpCAM conjugated molybdenum disulfide grafted reduced graphene oxide nanohybrid

An ultrasensitive, electrochemical biosensor has been fabricated by utilizing molybdenum disulfide (MoS2) grafted reduced graphene oxide (MoS2@rGO) nanohybrid as a sensing platform. Biomolecular-assisted synthetic method was adopted to synthesize MoS2@rGO nanohybrid, where L-cys was used to reduce GO. The MoS2@rGO nanohybrid exhibits improved electrochemical performance when it has been electrophoretically deposited onto the indium tin oxide (ITO) coated glass substrate. Further, epithelialcell adhesion moleculeantibodies (anti-EpCAM) specific to cancer biomarker has been covalently immobilized on the MoS2@rGO/ITO electrodes for label-free detection of EpCAM. Electrochemical results confirm that anti-EpCAM/MoS2@rGO/ITO based biosensor can detect EpCAM in the concentration range of 0.001–20 ng mL−1 with a detection limit of 44.22 fg mL−1 (S/N = 3). The biosensor's excellent analytical performance has been attributed to the efficient immobilization of EpCAM antibodies on the MoS2@rGO surface, which results in high specificity for EpCAM antigen. The fabricated biosensor showed good selectivity, reproducibility, and stability. The successful detection of EpCAM antigen in spiked samples (human saliva, serum and urine) makes this platform an alternative method for early screening of cancer biomarker.

MoS2 nanorods anchored reduced graphene oxide nanohybrids for electrochemical energy conversion applications

Herein, the hydrothermal route has been explored to design a novel network of molybdenum sulfide (MoS 2 ) nanorods/reduced graphene oxide (rGO) by varying wt% of MoS 2 (10–30 wt%) for the highly stable and efficient electrochemical energy conversion applications involving dye sensitized solar cells (DSSCs); and direct methanol fuel cells (DMFCs). The MoS 2 /rGO nanohybrids network has been systematically characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). XRD, HRTEM, Raman and XPS investigations confirmed the uniform and homogenous anchoring of MoS 2 nanorods on the rGO sheets in the MoS 2 /rGO nanohybrids. It has been revealed that the wt% of MoS 2 in MoS 2 /rGO nanohybrids strongly affects the anchoring of MoS 2 nanorods on rGO sheets which in turn affects their electrocatalytic behavior. The optimized MoS 2 /rGO nanohybrids with 20 wt% of MoS 2 nanorods exhibited long term stability and highly efficient electrocatalytic behavior. DSSCs assembled with MoS 2 /rGO nanohybrids as CE exhibited comparable power conversion efficiency (PCE) relative to standard DSSC. The optimized anchoring of MoS 2 on rGO sheets resulted in high current density as compared to rGO based electrocatalyst in MORs. Moreover, reproducibility of CV curves revealed high stability of MoS 2 /rGO nanohybrids under harsh electrolyte medium. • Synthesis of novel network of molybdenum sulfide nanorods (MoS 2 )/ reduced graphene oxide (rGO) using hydrothermal method. • Optimized MoS 2 /rGO nanohybrids (20 wt% of MoS 2 ) exhibits long term stability and high electrocatalytic behavior. • MoS 2 /rGO nanohybrids act as effective replacement of Pt electrocatalyst in DSSCs and methanol oxidation reactions in DMFCs.