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This paper studies in-situ synthesis of Fe2O3/reduced graphene oxide (rGO) anode materials by different hydrothermal process.Scanning Electron Microscopy (SEM) analysis has found that different processes can control the morphology of graphene and Fe2O3. The morphologies of Fe2O3 prepared by the hydrothermal in-situ and oleic acid-assisted hydrothermal in-situ methods are mainly composed of fine spheres, while PVP assists The thermal in-situ law presents porous ellipsoids. Graphene exhibits typical folds and small lumps. X-ray diffraction analysis (XRD) analysis results show that Fe2O3/reduced graphene oxide (rGO) is generated in different ways. Also, the material has good crystallinity, and the crystal form of the iron oxide has not been changed after adding GO. It has been reduced, and a characteristic peak appears around 25°, indicating that a large amount of reduced graphene exists. The results of the electrochemical performance tests have found that the active materials prepared in different processes have different effects on the cycle performance of lithium ion batteries. By comprehensive comparison for these three processes, the electro-chemical performance of the Fe2O3/rGO prepared by the oleic acid-assisted hydrothermal method is best.

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Here, we report an improved synthesis strategy for 3D nitrogen-doped graphene to increase the specific capacity of supercapacitors. Ethanol replaces the strong oxidant hydrogen peroxide in the improved Hummers method, and the loose porous structure is conducive to charge transfer. N-doped porous 3D graphene was synthesized from RGO-C prepared by ethanol secondary intercalation modification of functional groups. Ammonia was selected as the dopant; the microstructure and electrochemical performance of samples synthesized at different temperatures were examined. The results demonstrate that the 3D nitrogen-doped graphene (N-RGO-5) had a layered tuple shape with a sheet thickness of 0.612 nm.The specific surface area of the 3D N-RGO-5, which was prepared at 190°C, was 258.371 m2 g−1, which was higher than that (5.877 m2 g−1) of the original graphite. The 3D N-RGO-5 exhibited a specific capacitance of 236 F g−1 and an energy density of 32.78 Wh kg−1 at a current density of 1 A g−1, which is 27% higher than the specific capacitance of RGO. The 3D N-RGO-5 demonstrated an excellent capacity retention rate of 93.6% after 5000 cycles at a current density of 1 A g−1. This study demonstrates that the unique 3D structure and N-doping of N-RGO considerably improved the overall energy storage performance of graphene-based nanomaterials.

In this paper, the microstructure and wear resistance of Zr-17Nb alloy treated by high current pulsed electron beam were studied in detail. A phase change occurs after pulse treatments using X-Ray Diffraction (XRD) analysis, showing β (Nb) phase and α (Zr) phase transformed by a part of β (Zr, Nb) phase. Also, narrowing and shifting of β (Zr, Nb) diffraction peaks were found. Scanning Electron Microscope (SEM) and metallographic analysis results reveal that the microstructure of alloy surface before high current pulsed electron beam (HCPEB) treatment is composed of equiaxed crystals. But, after 15 and 30 pulse treatments, crater structures are significantly reduced. Besides, it was also found that the alloy surface has undergone eutectoid transformation after 30 pulse treatments, and the reaction of β (Zr, Nb) → αZr + βNb had occurred. Microhardness test results show that microhardness value presents a downward trend as the number of pulses increases, which is mainly due to the coarsening of the grains and the formation of a softer β (Nb) phase after phase transformation. The wear resistance test results show that the friction coefficient increases first, then decreases and then increases with the increase of pulse number.

Honeycomb graphene–polyaniline (HG–PANI) nanocomposites are synthesized through a facile electrostatic self-assembly approach, and the obtained material is characterized as the electrode for supercapacitor applications.