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When fabricated by thermal exfoliation, graphene can be covalently functionalized more easily by applying a direct ring-opening reaction between the residual epoxide functional groups on the graphene and the amine-bearing molecules. Investigation by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM) all confirm that these molecules were covalently grafted to the surface of graphene. The resulting dispersion in an organic solvent demonstrated a long-term homogeneous stability of the products. Furthermore, comparison with traditional free radical functionalization shows the extent of the defects characterized by TEM and Raman spectroscopy and reveals that direct functionalization enables graphene to be covalently functionalized on the surface without causing any further damage to the surface structure. Thermogravmetric analysis (TGA) shows that the nondestroyed graphene structure provides greater thermal stability not only for the grafted molecules but also, more importantly, for the graphene itself, compared to the free-radical grafting method.

We herein describe our use of a water-ethylene method to prepare a composite material consisting of platinum nanoparticles and graphene. Results obtained using XPS and XRD show that the degree of reduction of graphene was increased by the incorporation of Pt, and in addition, the increased concentration of defects was confirmed by the D/G ratio of the Raman spectra obtained. In comparison with Pt films, results obtained using CV and EIS showed that the electrocatalytic ability of the composite material was greater, and afforded a higher charge transfer rate, an improved exchange current density, and a decreased internal resistance. SEM images showed that the morphology of PtNP/ GR counter electrodes is characterized by a smooth surface, however, resulting in a lower resistance to diffusion, thereby improving the total redox reaction rate that occurs at the counter electrode. PtNP/ GR electrodes have a number of advantages over other electrodes that consist solely of graphene or Pt films, including a high rate of charge transfer, a low internal resistance, and a low resistance to diffusion. In our study, we showed that DSSCs that incorporate platinum-grafted graphene had a conversion efficiency of 6.35%, which is 20% higher than that of devices with platinized FTO.

Highly efficient blue organic light-emitting diodes (OLEDs) are necessary for high-resolution full-color displays and solid-state lighting applications.[1] The dopant-host system is often adopted to improve OLED performance. However, electroluminescence (EL) properties, including color purity, are extremely sensitive to the dopant concentration, [2] which is usually less than 2 wt % with a AE0.5 wt % variation. Precise control of the dopant concentration using co-evaporation methods is not an easy task. The development of highperformance blue-light-emitting materials suitable for nondoped OLEDs is one method of circumventing such fabrication problems. With many literature examples, nondoped-type