Huiyu Chen

Facile synthesis of highly porous N-doped CNTs/Fe3C and its electrochemical properties

Highly porous N-doped CNTs/Fe3C was synthesized by a facile and one-pot method. In this method, melamine was used as the carbon precursor; iron chloride was employed as a catalyst of graphic carbon and iron carbon source, and zinc chloride as a chemical activator to obtain highly porous structure. Fe3C nanorods were in situ formed and embedded into the inner structure of CNTs. The pore structure analysis shows that N-doped CNTs/Fe3C possesses the large specific surface area up to 1021.26 m2 g−1. The N-doped CNTs/Fe3C electrode exhibits a high specific capacitance of 181 F g−1 at the current density of 0.1 A g−1, and excellent capacitance rate and cycling stability.

Facile fabrication of porous flower-like α-Fe2O3 microspheres and their applications for water treatment

Abstract Flower-like α-Fe2O3 microspheres with an average diameter of about 1.5 μm were successfully synthesised with the assistance of ethylenediamine (EDA) through a facile high temperature solution method in ethylene glycol (EG) solvent. The morphologies and microstructure of the samples were characterised by scanning electron microscopy (SEM) and X-ray diffraction techniques. It was found that the size and morphology of the products were greatly influenced by the amount of EDA, EG and refluxing time, and a possible growth mechanism of such flower-like shape was proposed based on the controlled experiments. Because of the high specific surface area and porous structure, the α-Fe2O3 microflowers showed excellent adsorption performances with maximum removal capacities of 212 mg g−1 for Congo red in waste water treatment. The samples obtained from controlled experiments were also tested for the adsorption capacities, and the comparative dates were displayed distinctly. The prepared porous α-Fe2O3 spheres might have promising application in water treatment including the adsorption for toxic metal ions and the photocatalytic degradation.

A general route to the synthesis of PS/metal composites and their conversion to metal hollow microspheres

In this work, we put forward a simple and universal electroless plating approach to synthesize polystyrene/metal (PS/M) composite spheres, and hollow metal (e.g. Ni, Co, Cu) structures were also obtained after removing the PS core. Monodisperse PS microspheres were initially synthesized via a dispersion polymerization, and then these PS spheres activated with Pd served as templates for the synthesis of PS/M core–shell composite. The parameter of temperature was investigated in details, which strongly influenced the quality and morphology of metal coatings. Based on the above core–shell structures, the PS core template could be removed by ethyl acetate, and metal hollow spheres were formed finally. X-ray diffraction and scanning electron microscopy characterizations indicated that elemental Ni, Co, and Cu coatings with highly pure phase were successfully deposited onto the surfaces of PS microspheres. Such PS/M composites with low density would have wide applications in electromagnetic shielding fields.

Growth of wheel-like ZnO microstructures at low temperature

Abstract Wheel-like ZnO microstructures were synthesised via a simple and environmental benign chemical bath deposition at 90°C. The crystalline structure and shapes of the prepared ZnO were characterised by XRD and SEM techniques respectively. Such novel ZnO microstructures were constructed with many microsheets radiated from a hollow core, and the average size was ∼20 μm. Temperature and concentration of polyvinylpyrrolidone (PVP) were found to play important role in the formation of wheel-like morphology, and ZnO bidisks with different aspect ratio were also obtained by precisely synthesis control. The photoluminescence spectrum of the sample possessed a relatively strong UV emission at 382 nm and a very broad visible light emission.