One-Step Synthesis of SnO2/Carbon Nanotube Nanonests Composites by Direct Current Arc-Discharge Plasma and Its Application in Lithium-Ion Batteries

Advances and Applications of Carbon Nanotubes

Carbon nanotubes (CNT) (single-walled CNT, multiwalled CNT, non-covalently functionalized and covalently functionalized CNT, and/or CNT tailored with chemical or biological recognition elements) are by far the most popular nanomaterials thanks to their high electrical and thermal conductivities and mechanical strength, specific optical and sorption properties, low cost, and easy preparation, among other interesting characteristics [...].

PtRuFe/Carbon Nanotube Composites as Bifunctional Catalysts for Efficient Methanol Oxidation and Oxygen Reduction

The design of bifunctional catalysts with high performance and low platinum for the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR) is of significant implication to promote the industrialization of fuel cells. In our work, Pt/carbon nanotube (CNT), Pt₃Ru/CNT, and PtRu/CNT catalysts were synthesized by plasma heat treatment, in which the pyrolysis reduction of organometallic salts and the dispersion of CNTs were achieved simultaneously, and catalytic nanoparticles with uniform particle size were anchored on the dispersed CNT surface. Later, Fe was further introduced, and PtFe/CNT, Pt₃RuFe/CNT, and PtRuFe/CNT catalysts were synthesized by calcination, and the structure and electrochemical properties in both MOR and ORR of all as-synthesized catalysts were investigated. The results indicated that plasma thermal treatment has the advantage of rapidness and immediacy in the synthesis of catalysts, and the Pt/CNT, Pt₃Ru/CNT, and PtRu/CNT catalysts exhibited better electrocatalytic properties than commercial platinum (JM-Pt/C) catalysts. Meanwhile, the introduction of Fe during the calcination further changed the surface electronic properties of catalytic nanoparticles and enhanced the graphitization degree of catalysts; the PtRuFe/CNT catalyst exhibited outstanding electrocatalytic properties with a mass activity of 834.3 mA mg^-1 for MOR and a half-wave potential of 0.928 V in alkaline media for ORR. The combination of plasma thermal treatment and calcination puts forward a novel strategy for the optimization of catalysts, and the synthesis method based on plasma dispersion needs to be further optimized to achieve its large-scale promotion.