Structural Regulation and Electroconductivity Change of Nitrogen-Doping Reduced Graphene Oxide Prepared Using p-Phenylene Diamine as Modifier

Abstract

Using p-phenylene diamine (PPD) as a modifier and nitrogen resource, nitrogen-doping reduced graphene oxide was prepared by one-step refluxing method. The influence of PPD-GO (graphene oxide) mass ratio X on surface functional groups, layer structure, and electroconductivity of nitrogen-doping reduced grapheme oxide (NRGO-X) was investigated by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV-vis absorption spectrum, and electrical measurement. The results showed that GO can be simultaneously reduced and nitrogen-doped by PPD. When PPD-GO mass ratio X ≤ 6, there existed three types of N configurations in NRGO-X, including pyridinic N, pyrrolic N, and graphitic N. However, when X > 6, the pyridinic N disappeared in a six-membered ring. Further, the reduction process of NRGO as well as the nitrogen doping level and type can be regulated by changing the mass ratio X. With the increase of X, the d-spacing of NRGO-X layers increased first and then decreased, while the electrical conductivity increased gradually.

Effect of Reaction Temperature on Structure, Appearance and Bonding Type of Functionalized Graphene Oxide Modified P-Phenylene Diamine

“…To further verify the proposed hypothesis, XPS was performed on GO, FGO-70, and FGO-90 ( Figure 5 a). GO showed two spectral peaks at 286.0 and 535.0 eV, corresponding to C1s and O1s peaks, respectively [ 25 , 28 ]. By contrast, FGO-70 and FGO-90 displayed not only C1s and O1s peaks but also a new N1s peak near 401 eV, indicating the presence of N atom [ 27 , 36 ].…”

“…FGO-70 displayed characteristic peaks of C=C/C–C, C–O–C/C–O, and C=O. Finally, FGO-90 showed not only the above characteristic peaks but also a new peak at 285.9 eV, ascribed to C–N bond [ 28 , 36 ].…”

“…This may be explained as follows. Previous studies have suggested that benzene ring in PPD and its amine lone pair possess high resonance stability [ 25 , 28 , 36 ], reducing the reactivity of amine with epoxy groups. Moreover, the PPD’s aromatic ring has large steric hindrance, which would not allow it to either attack the carbon of GO nanosheet or undergo a ring-opening reaction with epoxy at low temperatures.…”

“…GO was prepared from natural graphite powder using the improved Hummers method. The detailed preparation method is described in our previous report [ 28 ].…”

Pd nanoparticles supported on reduced graphene oxide as an effective and reusable heterogeneous catalyst for the Mizoroki–Heck coupling reaction

“…The UV–visible (UV–Vis) absorption spectra of GO, rGO‐NH 2 , PdCl 2 , and PdNPs/rGO‐NH 2 are shown in Figure . The UV–Vis spectrum of GO dispersion in H 2 O shows one major peak at ~230 nm and a weak peak at ~310 nm due to π–π* absorption of C=C bonds and n–π* absorption of C=O bonds, respectively (Figure a). The UV–Vis spectrum of rGO‐NH 2 dispersion (Figure b) depicts a peak at ~260 nm, which confirms the chemical change in this material with respect to GO .…”