Graphene-like nanosheets synthesized by natural flaky graphite in Shandong, China

Abstract

Natural flaky graphite in Shandong, China was purified by H 2 O 2 , a new patent method to produce graphite without sulfur and used as precursor to prepare exfoliated graphite through microwave irradiated expansion with some chemicals (such as hydrogen peroxide, nitric acid, and acetic acid). With the centrifugation process, graphene was synthesized by using an efficient and simple method under ultrasonic and microwave irradiation at the room temperature. Natural graphite and exfoliated graphite were characterized by X-ray diffraction and scanning electronic microscopy, and the resultant graphene was investigated and confirmed by atomic force microscopy, Raman micro-spectrometer, etc. Natural graphite in Shandong, China, consisted of mainly hexagonal (2H) and a little rhombohedral structure (3R), was beneficial for the synthesis of graphene. Graphene-like nanosheets about 1 to 3 nm, around three to five carbon layers can be synthesized efficiently by microwave and ultrasonic irradiation with natural graphite.

Comparative studies on Graphite and Carbon Black powders, and their dispersions

“…Here, XRD of pure CB shows a broad peak at 24.7°, which confirms the amorphous nature of CB [46]. On the other hand, the XRD peak of pure Graphite occurs at 26.5°, inferring that it's d-spacing (3.34 Å) resembles the one of pristine Graphite [47,48] having hexagonal structure (2H). This seems to be one of the reasons why amorphous CB is having better dispersion behaviour in solution media due to the absence of long range order.…”

Microwave heating of carbon-based solid materials

“…)The most notable features of microwave exfoliation are immediacy and effectiveness. The exfoliation is completed within a minute in most cases [23,[25][26][27][28][29], and higher volume expansion is observed than with the conventional method using an electrical furnace at over 1000°C [25,28] (Table 3). In addition, relatively uniform expansion [21], dry- [20].…”

A novel one-step synthesis for carbon-based nanomaterials from polyethylene terephthalate (PET) bottles waste

“…That can be explained, as, in the oxidation duration of formed graphite from PET decomposition, oxidation occurs at the edges of flake graphite first and then oxidants enter the inner layers (Xiu, 2013). Oxide radicals induced cutting along the edges and surface defects of graphite (Xiu, 2013;Li et al, 2009). Under thermal decomposition, formed graphite expanded rapidly because of the decomposing of the oxidants between the layers.…”