, and used as received without further purification.2.1. Preparation of GOIn a typical procedure, GO was first prepared from pure graphite using a modified Hummer’s method [27,28]. Briefly, 2.0 g of natural graphite powder was added to 300 mL of H2SO4 namely under stirring at 0 ��C, and then 3.0 g of NaNO3 and 20 g of KMnO4 were added gradually. Successively, the mixture was transferred to a water bath at 30 ��C and stirred for 20 min to form a thick paste. Then, 250 mL of distilled water was slowly added and the temperature was increased to 98 ��C. After 30 min aging, another 500 mL of water was added and this was followed by a dropwise addition of 40 mL of H2O2 (30%). When the color of the solution changed from dark brown to brilliant yellow, the mixture was filtered and washed with diluted HCl aqueous (1/10 v/v) three times to remove metal ions, and then washed with distilled water repeatedly until the pH became 7.
Finally, the as-prepared GO was obtained after drying in a vacuum oven at room temperature.2.2. One-Step Microwave-Assisted Inhibitors,Modulators,Libraries Growth of Ni Nanospheres on rGO SheetsNext, 0.058 g of Ni(NO3)2?6H2O and 10 mg of the as-prepared GO were dissolved in 40 mL of EG with the assistance Inhibitors,Modulators,Libraries of ultrasonication for 1 h. Subsequently, the mixture was transferred to an oil bath under vigorous stirring, and then 2 mL of hydrazine monohydrate (N2H4?H2O, 85%) was slowly added and the solution was placed in a microwave refluxing system irradiated Inhibitors,Modulators,Libraries Inhibitors,Modulators,Libraries at 300 W for 20 min. Finally, the as-prepared products were collected and thoroughly rinsed several times with distilled water and ethanol and then dried at 60 ��C for 12 h.
2.3. CharacterizationPowder X-ray diffraction (XRD) measurements of the samples were performed with a Philips PW3040/60 X-ray diffractometer using CuK�� radiation at a scanning rate of 0.06��s?1. Fourier transform infrared (FT-IR) spectra were recorded Anacetrapib on a Nicolet NEXUS670 FT-IR spectrometer using KBr pellets. Scanning electron microscopy (SEM) was performed with a Hitachi S-4800 scanning electron microanalyzer with an accelerating voltage of 15 kV. Transmission electron microscopy (TEM) and high resolution TEM were conducted at 200 kV with a JEM-2100F field emission TEM, after dispersing the Ni-rGO nanohybrids in ethanol and depositing several drops of the suspension on the carbon coated copper grids and dried under ambient conditions.2.4.
Electrochemical MeasurementsAll electrochemical measurements were conducted using a CHI840C electrochemical workstation with conventional three-electrode setup at room temperature. A Ni-rGO hybrids modified GCEs was employed as working electrode, a saturated Hg/Hg2Cl2 electrode (SCE) as reference electrode and platinum wire as counter electrode. The supporting electrolyte is 0.1 M NaOH sellckchem containing 0.1 M KCl, and deionized water was used throughout the experiments.