Efficient amine functionalization of graphene oxide through the Bucherer reaction: an extraordinary metal-free electrocatalyst for the oxygen reduction reaction

Abstract

A simple and reliable method based on the Bucherer reaction is proposed for the functionalization of graphene oxide (GO) with amine (-NH 2 ) groups. In the proposed method the chemical reaction between ammonia and GO ,as the precursor materials, is catalyzed with sodium bisulfite. The prepared amino-reduced graphene oxide (amino-r-GO) was characterized with spectroscopic and imaging techniques including FT-IR, XRD, XPS, SEM, EDX elemental mapping and thermal-gravimetric analysis (TGA). The surface analysis and material characterization reveal the high percentage of amine functional groups can be achieved via this method. The investigation of electrocatalytic activity of the prepared amino/r-GO toward oxygen reduction reaction confirms the significant improving the catalytic activity of amine functionalized graphene surface in the vicinity of doped nitrogen in same graphene framework.The onset potential of ORR vs. Ag/AgCl in 0.1 M KOH solution is observed at -0.05 V and peak current density is 1.15 mA cm -2 comparable to observed values for Pt/C as electrocatalyst (onset potential -0.04 and peak current density 1.17 mA cm -2 ) . This prepared amino/r-GO is so important to future research for the extension of various graphene-based composites.The reaction is completed in a typical autoclave tube over night at the temperature of ~170 °C.During the single displacement reaction in hydrothermal condition, phenolic oxygen located at the surface and the edge plane of GO, are replaced by -NH 2 groups resulting in amino-Gr.Moreover, during the hydrothermal condition the epoxy groups are removed and the GO platelets are reduced to r-GO nanosheets.It is well known that Bucherer reaction is the reversible conversion of naphthol to naphthyl amine. In the case of GO functionalization process, the initial reactants have a high dispersibility or frequently, solubility in aqueous solution while, after amine functionalization the resultant product (amino-rGO) is almost insoluble, even its dispersibility in water is drastically decreased compare to GO. Therefore, we believe the amination process of GO through bucherer reaction is mostly proceed in the forward direction, so this process has a little reversibility.As discussed above, GO has a higher dispersibility rather than amines functionalized GO in water. Moreover, the single sheets of GO are dissolved in water after dispersion and the color of solution changed to yellow. Hence, the exfoliated GO might be better for functionalization but

A Polyallylamine Anchored Amine‐Rich Laser‐Ablated Graphene Platform for Facile and Highly Selective Electrochemical IgG Biomarker Detection

“…However, LAG can be obtained by simply burning polymide film (PI, Kapton) with a laser scribing method under an ambient environment 15. Due to its straightforward availability and its easy preparation method, LAG become attractive for scientific research and widely used in the field of biosensors, hydrogen evolution reaction, and flexible super capacitors 14,22–25. As the binding of biomolecules is a major concern for the immunosensor development, we have introduced polycationic polyallylamine (PAAMI) on the LAG substrate by noncovalent π–π interaction and electrostatic physical absorption 26,27.…”

“…[15] Due to its straightforward availability and its easy preparation method, LAG become attractive for scientific research and widely used in the field of biosensors, hydrogen evolution reaction, and flexible super capacitors. [14,[22][23][24][25] As the binding of biomolecules is a major concern for the immunosensor development, we have introduced polycationic polyallylamine (PAAMI) on the LAG substrate by noncovalent π-π interaction and electrostatic physical absorption. [26,27] It provide anchoring sites for the biomolecule, boosts electron transfer rate, as well as increases stability of LAG.…”

Flexible gold nanoparticles/rGO and thin film/rGO papers: novel electrocatalysts for hydrogen evolution reaction

“…6(c)] can be deconvoluted into four main peaks with binding energies of 283.7, 285.5, 286.5 and 287.6 eV, which are assigned to C C, C-O, O-C-O and O-C=O, respectively. 44,45 After chemical reduction by HI, the intensities of the O-dominated groups (hydroxyl and epoxy groups) were remarkably decreased and the C C and C-H bonds remained dominant compared to XPS data for the GO paper, as shown in Fig. S8.…”

Synthesis of Optically Pure Arylamine Derivatives by Using the Bucherer Reaction

“…Furthermore, arylamine 2 can be prepared using this kind of transition‐metal catalysed reaction starting from 2,6‐dibromonaphthalene (Scheme ) . Recently, an efficient amine functionalization of graphene oxide at Bucherer conditions was reported . An alternative approach to less enantioenriched products uses the borane‐catalyzed reduction of imine species .…”