Search

Graphene-supported uranium dioxide (UO 2 ) nanocrystals are potentially important fuel materials. Here, we investigate the possibility of synthesizing graphene-supported UO 2 nanocrystals in polar ethylene glycol compounds by the polyol reduction of uranyl acetylacetone under boiling reflux, thereby enabling the use of an inexpensive graphene precursor graphene oxide into a one-pot process. We show that triethylene glycol is the most suitable solvent with an appropriate reduction potential for producing nanometer-sized UO 2 crystals compared to monoethylene glycol, diethylene glycol, and polyethylene glycol. Graphene-supported UO 2 nanocrystals synthesized with triethylene glycol show evidence of heteroepitaxy, which can be beneficial for facilitating heat transfer in nuclear fuel particles. Furthermore, we show that graphene-supported UO 2 nanocrystals synthesized by polyol reduction can be readily stored in alcohols, impeding oxidation from the prevalent oxygen in air. Together, these methods provide a facile approach for preparing and storing graphene-supported UO 2 nanocrystals for further investigation and development under ambient conditions. [ABSTRACT FROM AUTHOR]

The development of accurate, reliable and low cost devices for glucose detection is one of the most important scientific and technological hotspots. In this study, we proposed a unique one-step thermal synthesis strategy to synthesize nickel (Ni) nanoparticles modified graphene (GE) sheets by using metal-oleate complex as the precursor and sodium sulfate as a template. With the assistance of sodium sulfate particles, Ni nanoparticles with particle size of about 99.2 nm were homogenously anchored on graphene nanosheets in the product. The electrochemical behavior of the nanocomposite towards enzyme-free glucose oxidation was investigated systematically by cyclic voltammetry and amperometric measurements. The results reveal that the GE/Ni nanocomposite exhibited excellent electrocatalytic response to glucose with a wide linear range of 0.01–2.5 mM, a low detection limit of 0.79 μM, and a high sensitivity of 388.4 μA mM −1 cm −2 . In addition, no significant interference was observed from potential interference species. The simple, efficient and scalable synthesis and the excellent catalytic performance endow the GE/Ni nanocomposite great potential application in enzymeless glucose detection. [ABSTRACT FROM AUTHOR]

In this study, reduced graphene oxide (RGO) supported Ni nanoparticles were synthesized by a facile in-situ refluxing approach using triethylene glycol as both reductive and dispersing agent. The as-synthesized RGO/Ni nanocomposites were characterized by X-ray diffraction, Raman spectroscopy and transmission electron microscopy, which revealed that Ni nanoparticles with hexagonal close-packed structure were homogeneously dispersed on the surface of RGO sheets. The catalytic activity and electrochemical properties of the RGO/Ni nanocomposites were investigated. It is found that the RGO/Ni nanocomposites exhibit markedly enhanced catalytic activity toward the reduction of p -nitrophenol by NaBH 4 , which is comparable to noble metal catalyst. The RGO/Ni nanocomposites also exhibited excellent electrocatalytic response to glucose. The linear range, detection limit and sensitivity were estimated to be 0.01–3.0 mM ( R 2 = 0.997), 2.8 μM and 535.258 μA mM −1 cm −2 , respectively. It is expected that this facile method presented here could be extended to synthesize other RGO/metal nanocomposites with various functions. [ABSTRACT FROM AUTHOR]