Graphene Oxide Hybrid Nanomaterial Research Articles

Strategically engineered multifunctional graphene oxide hybrid nanomaterials for efficient catalytic degradation and emerging contaminants treatment

The use of functional textiles is growing in all fields of science and technology. Surface functionalization is mainly used to impart conventional textiles with new functionalities and improved performances. In the present study, a cobalt ferrite nanoparticle/graphene oxide (CoFe2O4/GO) coated polyethylene terephthalate (PET) fabric with excellent catalytic and antibacterial properties, has been successfully developed. The PET-coated CoFe2O4/GO samples, ranging from 1 % to 5 % wt. were obtained using a simple dip-coating method in CoFeO/GO solution (1 mg/mL), and were investigated through several physiochemical characterization techniques. CoFe2O4/GO and PET fabric have been shown to establish an interfacial connection by Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) results showed that CoFe2O4/GO coating did not affect the PET crystallinity and that CoFe2O4/GO hybrid was incorporated in the PET samples, which was proved as well by the morphological study through Scanning electron microscopy (SEM). Furthermore, thermogravimetric characterisation (TGA) verified that the coating does not change or impair the quality of the fibre and that the PET@CoFe2O4/GO as made is thermally stable. Tensile strength tests demonstrated that coated fabrics exhibited outstanding mechanical properties in comparison with pristine PET. Moreover, the coated PET@CoFe2O4/GO fabric was used as a model catalytic system for peroxymonosulfate (PMS) activation in the rhodamine B (RhB) degradation reaction. Total Organic Carbon (TOC) measurements showed that TOC removal reached 89.82 % in only 12 min reaction. The results confirmed that the coated fabrics exhibited high catalytic performances, good stability and reusability in consecutive degradation experiments with a degradation rate over 60 % even after 7 degradation cycles; Moreover, it is easily and simply separated from the mixture, by removing the textile sample from the aqueous solution. It is worth mentioning that the PET@CoFe2O4/GO fabrics showed outstanding antibacterial activity against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria with an inhibition diameter zone of up to 13 mm for PET@CoFe2O4/GO (5 %). Overall, these findings are of great importance as they permit the development of a novel multifunctional textile fabric, combining anti-bacterial activity, catalytic performance and mechanical properties. The study provides a textile-based catalyst with improved catalytic performance, re-usability in consecutive degradation reactions and easy catalyst separation compared to traditional supports. Thus, a huge potential application in several fields such as medicine, heterogeneous catalysis, and wastewater treatment.

Sensitive electrochemical biosensor for bisphenol A based on laccase immobilized on polypyrrole‐3‐carboxylic/Sb2O5/reduced graphene oxide hybrid nanomaterial

AbstractAn electrochemical biosensor for the bisphenol A determination was constructed onto a glassy carbon electrode modified with a hybrid nanostructure based on polypyrrole‐3‐carboxylic acid/Sb2O5/reduced graphene oxide and laccase enzyme. The hybrid nanostructure was characterized by X‐ray photoelectron spectroscopy (XPS), HR‐TEM, SEM microscopy, and electrochemical techniques. The biosensor displayed excellent response for bisphenol A determinations by differential pulse voltammetry, showing a theoretical detection limit of 9.9 nmol L−1 in the linear range of 0.1–1.0 μmol L−1. The biosensor demonstrated excellent selectivity in the determinations of bisphenol A in tap water without significant interference from other species, such as 17β‐estradiol, Estriol, Progesterone, Catechol, Hydroquinone, Ascorbic acid, and Dopamine. The biosensor also has presented an excellent performance in bisphenol A determinations in water, with recovery tax ranging from 99.6 to 101 %. Therefore, it can be used satisfactorily to detect bisphenol A in real samples.

New Water Oxidation Electrocatalyst Based on the Cobalt-Containing Polyoxometalate-Reduced Graphene Oxide Hybrid Nanomaterial.

A new hybrid nanomaterial based on the immobilization of cobalt-containing polyoxometalate (CoPOM) on the surface of reduced graphene oxide (rGO) was designed for an efficient electrocatalytic water splitting reaction. First, the surface of rGO was functionalized with aminopropylsilyl groups and protonated with hydrochloric acid to produce ammonium groups. Then, the electrostatic interaction of positively charged rGO-supported ammonium groups with anionic CoPOM produced a CoPOM-APTS-rGO hybrid nanomaterial. The achieved hybrid nanomaterial exhibited a low overpotential of 128 mV versus NHE at a current density of 10 mA cm-2 in the electrocatalytic water oxidation at pH 7. In addition, a fast reaction kinetic with a Tafel slope of 74 mV dec-1 was seen in the presence of the prepared hybrid nanomaterial. Linear sweep voltammetry analysis revealed the long-term stability and activity of CoPOM-APTS-rGO for water oxidation in neutral conditions.

Black Phosphorus: Black Phosphorus–Graphene Oxide Hybrid Nanomaterials toward Advanced Lubricating Properties under Water (Adv. Mater. Interfaces 23/2019)

Black Phosphorus: Black Phosphorus–Graphene Oxide Hybrid Nanomaterials toward Advanced Lubricating Properties under Water (Adv. Mater. Interfaces 23/2019)

Black Phosphorus–Graphene Oxide Hybrid Nanomaterials toward Advanced Lubricating Properties under Water

Abstract2D hybrid nanomaterials show great potential in reducing friction and energy dissipation of dry sliding both theoretically and experimentally. However, the achievement of low friction by introducing the hybrid nanomaterials in a macroscopic water‐based environment remains a major challenge. Here, black phosphorus–graphene oxide (BP‐GO) hybrid nanomaterials with a 2D layered structure are synthesized successfully. As water‐based additives, the BP‐GO hybrid nanomaterials enable the significant reduction of friction and wear. The lubrication mechanism proposed involves the easy interlayer shear that originated from the hydrophilization and unique microscopic heterojunction stacking structure of the 2D BP‐GO hybrid nanomaterials. This study demonstrates the fascinating prospect of the 2D BP‐GO hybrid nanomaterials toward advanced macroscopic lubricating properties under water.

A polyethyleneimine-grafted graphene oxide hybrid nanomaterial: Synthesis and anti-corrosion applications

In this work, a polyethyleneimine-grafted graphene oxide (PEI-GO) hybrid material was prepared as an effective filler to improve the anticorrosion performance of waterborne epoxy coating. The successful covalent reaction between PEI and GO was confirmed by FTIR, Raman, XPS, XRD and TGA measurement. The epoxy coating filled with modified and unmodified graphene oxide was characterized by SEM and Raman spectroscopy. The results showed that PEI-GO was uniformly dispersed in the epoxy matrix. It was found that the PEI-GO hybrid materials displayed considerable superiorities in improving corrosion resistance of epoxy coating by EIS and SVET. Besides, the optimal content (0.25 wt%) of PEI-GO was obtained through experimental results. Moreover, the desirable anticorrosive property of PEI-GO/EP composite coating is proposed to be mainly attributed to the role of PEI, which fully stimulated the barrier properties of graphene oxide by improving its dispersion in the epoxy coating and also enhanced the crosslink density of epoxy resin by increasing the surface activity of the graphene oxide to the epoxy groups.

Electrochemical determination of methyl parathion based on pillar[5]arene@AuNPs@reduced graphene oxide hybrid nanomaterials

The detection of pesticides has become a very important and critical research area because of the rapid development of agriculture and strict environmental protection regulations.

Reduced Graphene oxide / Nanoparticle hybrid structures: A new generation smart materials for optical sensors

Graphene oxide/reduced Graphene oxide hybrid nanomaterials have been widely used as substrates for surface enhanced Raman spectroscopy. This is mainly due to that they have unique structures and inherent properties including highest specific surface area, chemical and electrochemical inertness and easy surface modification etc. It is the parent of all graphite form and is an interesting topic of research in the last three to four years. It can be stacked to form 3D graphite, rolled to form ID nanotubes and wrapped to form 0D fullerenes. The long-range π-conjugation in graphene shows extraordinary thermal, mechanical and electrical properties. The carbon nanomaterial-based spectroscopy detection of chemical and biological molecules has gained much attention with its extensive applications to genomic, proteomic and environmental analysis as well as for clinical diagnosis.Surface enhanced Raman (SERS) spectroscopyhas proven to be an effective technique for analyzing the innovative nanomaterials, graphene. This technique has also helped in identifying some unique properties ofgrapheneas a Raman substrate for the suppression of fluorescence. The requirement for a substrate that is biocompatible, chemically inert, and capable of Raman enhancement is a major technological objective and grapheneserves as a suitable material.

An ionic liquid-graphene oxide hybrid nanomaterial: synthesis and anticorrosive applications.

Herein, an ionic liquid-graphene oxide hybrid nanomaterial was prepared via a facile grafting reaction between an imidazole ionic liquid and graphene oxide. FTIR, Raman, and XPS spectra demonstrated that imidazole ionic liquids were successfully covalently attached to the surface of graphene oxide nanosheets. The resulting hybrid nanomaterial, with a thickess of ca. 3 nm, can be stably dispersed in water. Results obtained from electrochemical impedance spectroscopy revealed that ionic liquid-graphene oxide hybrids effectively improved the anticorrosion performance of epoxy-based waterborne coatings. Moreover, ionic liquids performed two functions: (a) they facilitated the dispersion of graphene in a polymer matrix and then utilized the impermeable barrier capability of graphene and (b) they endowed the graphene sheets with a corrosion inhibition effect. The scanning vibrating electrode technique combined with electrochemical tests proved that the enhanced protective performance of the as-prepared composite coatings was attributed to the synergistic effect of the impermeable property of graphene nanosheets and the inhibitory function of the imidazole-based ionic liquid.

Cuprous Sulfide/Reduced Graphene Oxide Hybrid Nanomaterials: Solvothermal Synthesis and Enhanced Electrochemical Performance

The cuprous sulfide nanoparticles (CuS NPs)-decorated reduced graphene oxide (rGO) nanocomposites have been successfully prepared via a facile and efficient solvothermal synthesis method. Scanning electron microscopy and transmission electron microscopy images demonstrated that CuS micronspheres composed of nanosheets and distributed on the rGO layer in well-monodispersed form. Fourier-transform infrared spectroscopy analyses and x-ray photoelectron spectroscopy showed that graphene oxide (GO) had been reduced to rGO. The electrochemical performances of CuS/rGO nanocomposites were investigated by cyclic voltammetry and charge/discharge techniques, which showed that the specific capacitance of CuS/rGO nanocomposites was enhanced because of the introduction of rGO.

TiO2–RGO hybrid nanomaterials for enhanced water splitting reaction

The production of H2 via photocatalytic water splitting reaction has attracted a great attention as a clean and renewable energy for next generation. Despite tremendous efforts, the present challenge for materials scientist is to develop highly active photo catalysts for splitting of water at low cost. This article reports the synthesis of TiO2-reduced graphene oxide hybrid nanomaterials through ionothermal method using functionalized ionic liquid for the enhanced hydrogen generation via water splitting reaction. The structural and morphological properties of the samples were investigated by XRD, Raman spectroscopy, TG-DTA, UV–vis spectroscopy and TEM. A substantial increase of H2 evolution was observed for TiO2-reduced graphene oxide hybrid nanomaterials. This is due to the high migration efficiency of photo-induced electrons and the inhibition of charge–carrier recombination due to the electronic interaction between TiO2 and reduced graphene oxide. i.e, reduced graphene oxide acts as an electron-acceptor which effectively hinders the electron–hole pair recombination of TiO2.