Kui Lin

Preparation of novel silicon/nitrogen-doped graphene composite nanosheets by DC arc discharge

Silicon/graphene nanocomposites (Si/GNCs) are one of the promising candidates for the increasing demands of portable electronic devices and electric vehicle applications. However, two-dimensional (2D) Si phase component in Si/GNCs was rarely reported. In this work, we present the preparation of Si/nitrogen-doped graphene composite nanosheets (Si/NDGCNSs) by DC arc discharge under nitrogen of 800 °C, using an anode with comparatively high Si content and good homogeneity. 2D Si nanostructures were observed in the Si/NDGCNSs. The phase composition of the Si/NDGCNSs includes graphitic carbon, Si and silicon carbide (SiC). The suspensions of the Si/NDGCNSs in distilled water and ethanol were stable for more than one and two months respectively, and both of them emitted green luminescence under irradiation of UV light. Their UV-vis spectra show two absorption peaks. The formation mechanism of the Si/NDGCNSs is discussed briefly. The as-prepared Si/NDGCNSs may be used for photocatalysts, solar cells and energy storage devices, etc.

Preparation of N-Doped Composite Shell Encapsulated Iron Nanoparticles and Their Magnetic, Adsorptive, and Photocatalytic Properties

The N-doped composite shell encapsulated iron nanoparticles (CSEINPs) were prepared by DC arc discharge under nitrogen at 800°C, using the anode with high Fe content and good homogeneity. The morphology, microstructure, composition, and some properties of the N-doped CSEINPs were characterized by various characterization techniques. The results revealed that the shells of the N-doped CSEINPs were composed of homogeneously amorphous structure containing C, Fe, O, and N elements; the saturation magnetization (Ms) and coercivity (Hc) of them at room temperature were 130źemu/g and 194źOe, respectively. Due to the surface structure and the electrostatic interaction, the N-doped CSEINPs are employed to remove methylene blue (MB) from the waste solution, and they exhibited high adsorption properties and photocatalytic activity under irradiation of visible light (IVL). The kinetics of adsorption of MB on the N-doped CSEINPs was investigated and the recycling test was carried out. The formation mechanism of the N-doped CSEINPs is discussed briefly.