A novel preparation method of carbon nanotubes by spinning core/shell polymer particles

A novel preparation method of carbon nanotube (CNT) was developed by using a polymer blend technique. Two kinds of polymers are used as raw materials: one is polyacrylonitrile (PAN) as a carbon precursor polymer and another is polymethylmethaerylate (PMMA) as a thermally decomposable polymer without carbon residue. Fine three-layered core/shell polymer particles with a PMMA/PAN/PMMA structure were synthesized by a soap-free emulsion polymerization method using potassium persulfate as a radical initiator. The particles were ca.500nm_in diameter and quite uniform. They were melt-spun, stabilized and finally carbonized at 1000__at which CNTs of 10-20nm in diameter were derived from PAN after removal of PMMA. The PMMA core and the outer PMMA shell played the roles of forming hollow tubes and avoiding fusing of PAN shells at melt-spinning process, respectively

Carbon-based catalyst support in fuel cell applications

Ji Liang, Shi Zhang Qiao, Gao Qing (Max) Lu and Denisa Hulicova-Jurcakov

Enhanced electrochemical catalytic activity by copper oxide grown on nitrogen-doped reduced graphene oxide

A copper oxide/nitrogen-doped reduced graphene oxide (CuO/N-rGO) nanocomposite is synthesized through a low-temperature aqueous process. The resultant nanocomposite is characterized by spectroscopies which show significant interaction between copper and nitrogen. Electrochemical tests show that the nanocomposite exhibits superior oxygen reduction (ORR) activity, which is significantly higher than that of both N-rGO and CuO/GO, and is close to that of commercial Pt/C. Further mechanistic study confirms that the enhancement of ORR activity is prompted by the synergistic effect of copper and nitrogen, which largely accelerates the electrochemical reduction of the peroxide reaction intermediate on N-rGO during ORR, leading to higher onset potential, larger current density and electron transfer number. Larger porosity created by CuO intercalation also helps to lift the limiting current. The CuO/N-rGO not only serves as an alternative to the expensive Pt based ORR electrocatalyst due to its low price but is also promising for other applications such as peroxide/borohydride fuel cells and H2O2 detection/elimination. The study also gives an insight into the study method and mechanism of the metal-nitrogen synergistic effect on electrochemical catalysis which may inspire development of other new cost-effective electrocatalysts. © 2013 The Royal Society of Chemistry.Ruifeng Zhou, Yao Zheng, Denisa Hulicova-Jurcakova and Shi Zhang Qia