Raman spectrum of graphene and graphene layers.
TL;DR: This work shows that graphene's electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers, and allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.
Abstract: Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process The G peak slightly down-shifts This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area
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TL;DR: In this article, a 3D hydrogel of titanium dioxide (TiO2)-graphene was fabricated using a simple one-pot method and exhibited enriched adsorption-photoelectrocatalytic degradation ability of low-concentration bisphenol A (BPA).
Abstract: We successfully fabricated the three-dimensional (3D) hydrogel of titanium dioxide (TiO2)-graphene using a simple one-pot method and exhibited enriched adsorption-photoelectrocatalytic degradation ability of low-concentration bisphenol A (BPA). Combined with the unique adsorption of graphene hydrogel and the effective photoelectrocatalytic performance of TiO2, we rapidly enriched the organic pollutants and conducted efficient in situ degradation. The low-concentration BPA (20 mg/L) was degraded completely by the TiO2-rGH electrode in 5 h through the synergistic effect of adsorption-photoelectrocatalytic. The photogenerated charge on the surface of TiO2 is rapidly separated by the action of the applied electric field and the graphene sheet. The high conductivity of the graphene makes the TiO2-graphene hydrogel rapidly conducting the charge and solves the problem of poor conductivity of the semiconductor electrode. On the basis of these advantages, the TiO2-rGH has a cross-porous network structure that favors the anchor of more TiO2 nanocrystals, the specific surface area and reactive sites are greater than the thin film electrode, and the structure is conducive to significantly improving the BPA removal efficiency. By contrast, the BPA degradation of TiO2-rGO thin film electrode was 40% after 4 h of ultraviolet irradiation, whereas the removal rate of BPA over the same mass of TiO2-rGH electrode rate was up to 96%. At the same time, the TiO2-rGH electrode without filtering can be achieved quickly separated from the recovery due to its special macro-3D network structure. Its removal ability still maintains above 90% after 10 times cyclic experiments with self-regeneration characteristics. It can be achieved rapid separation and recovery without filtering.
275 citations
TL;DR: The high stability in electronic performance of the devices upon bending up to ±2.2 mm in compressive and tensile modes, and the ability to recover electrical properties after degradation upon annealing, reveal the efficacy of using 2D materials for creating highly flexible and transparent devices.
Abstract: A highly flexible and transparent transistor is developed based on an exfoliated MoS2 channel and CVD-grown graphene source/drain electrodes. Introducing the 2D nanomaterials provides a high mechanical flexibility, optical transmittance (∼74%), and current on/off ratio (>10(4)) with an average field effect mobility of ∼4.7 cm(2) V(-1) s(-1), all of which cannot be achieved by other transistors consisting of a MoS2 active channel/metal electrodes or graphene channel/graphene electrodes. In particular, a low Schottky barrier (∼22 meV) forms at the MoS2 /graphene interface, which is comparable to the MoS2 /metal interface. The high stability in electronic performance of the devices upon bending up to ±2.2 mm in compressive and tensile modes, and the ability to recover electrical properties after degradation upon annealing, reveal the efficacy of using 2D materials for creating highly flexible and transparent devices.
274 citations
TL;DR: In this paper, a solution of polyvinylpyrrolidone under sonication results in water-soluble, polymer-protected graphene single layers without oxidation or destruction of the sp2 character of the carbon core.
274 citations
TL;DR: It is demonstrated that, in general, multilayer graphene will give rise to higher levels of reinforcement than monolayer material, with the optimum number of layers depending upon the separation of the graphene flakes in the nanocomposite.
Abstract: The stress transfer between the internal layers of multilayer graphene within polymer-based nanocomposites has been investigated from the stress-induced shifts of the 2D Raman band. This has been undertaken through the study of the deformation of an ideal composite system where the graphene flakes were placed upon the surface of a polymer beam and then coated with an epoxy polymer. It is found that the rate of band shift per unit strain for a monolayer graphene flake is virtually independent of whether it has one or two polymer interfaces (i.e., with or without an epoxy top coating). In contrast, the rate of band shift is lower for an uncoated bilayer specimen than a coated one, indicating relatively poor stress transfer between the graphene layers. Mapping of the strain in the coated bilayer regions has shown that there is strain continuity between adjacent monolayer and bilayer regions, indicating that they give rise to similar levels of reinforcement. Strain-induced Raman band shifts have also been eva...
273 citations
TL;DR: Red blood cell like-mesoporous carbon hollow microspheres (RBC-PCHMs) have been synthesized by modified stober method with following pyrolysis and etching procedures.
273 citations
References
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28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations