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In the present work, graphene oxide nanoribbons (GONRs) were synthesized via the longitudinal unzipping of multi-walled carbon nanotubes (MWCNTs) nanoparticles with the aid of strong oxidants. The MnO 2 /reduced graphene oxide Nanoribbons (MnO 2 /rGONRs) composites were successfully fabricated by means of a reproducible and single-step hydrothermal co-reduction of KMnO 4 and GONRs. The morphology and composition of as-prepared materials were studied by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). The as-prepared MnO 2 /rGONRs were employed in fabricating a nonenzymatic electrochemical sensor for the sensitive detection of hydrogen peroxide (H 2 O 2 ). The electrochemical properties of the MnO 2 /rGONRs modified glassy carbon electrode (MnO 2 /rGONRs/GCE) were studied by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The developed nonenzymatic electrochemical sensor exhibited well-defined amperometric response towards H 2 O 2 in a wide linear range of 0.25–2245 μM, and a detection limit of 0.071 μM (S/N = 3) could be obtained. And the proposed sensor also displayed excellent electrochemical analytical performance, acceptable reproducibility, high accuracy, and great anti-interference ability. The proposed sensor was applied for the determination of H 2 O 2 in real sample of fetal bovine serum (FBS), and acceptable accuracy and recovery could be obtained. [ABSTRACT FROM AUTHOR]

Abstrat In this work, a novel sandwich-structured graphene-based composite (PPD-GO) was prepared. The graphene-based composite was prepared by amination of graphene oxide (GO) with p -phenylenediamine (PPD) with the aid of the coupling reagents. And PPD was introduced into the interlayers of graphene nanosheets. The morphology, composition, and grafted functional groups of the composite were investigated by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. And PPD-GO was used as a highly efficient adsorbent for removal of Congo red from used from aqueous solutions. The whole adsorption process was studied in depth and elucidated systematically. A maximum Congo red adsorption capacity of 892.8 mg/g was obtained for PPD-GO composite at an initial temperature of 298 K and pH of 3.0. The second-order kinetic equation could well describe the sorption kinetics. The equilibrium data were perfectly fitted by the Langmuir isotherm. The thermodynamic analysis indicated that the adsorption of Congo red onto the PPD-GO composite was a spontaneous and endothermic process. [ABSTRACT FROM AUTHOR]