| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 102 === Single wall carbon nanohorns (SWNHs) is classified as one allotrope of nanocarbons which possesses interstitial and internal pores because of its unique spherical structure. Abundant spaces and sites make it become an attractive material for various applications, but prior treatment is needed in order to produce a versatile SWNHs. Facile method to introduce abundant carboxyl groups as well as to increase total surface area of SWNHs was investigated by oxidizing it with mild [HNO3]. With optimum time of 40 min to 1 h oxidation, carboxyl group functionalized, large surface area and well-dispersed SWNHs in water can be produced while maintaining its pristine morphological structure. Moreover, SWNHs-ox that was produced can be easily purified from graphite impurities, yielding an impurities-free SWNHs-ox.
Current research of versatile SWNHs-ox can be used as a support for platinum nanoparticles (PtNPs) by means of amine-terminated fourth generation poly(amidoamine) (PAMAM) dendrimer (G4-NH2). With the existence of G4-NH2, dendrimer-encapsulated platinum nanoparticles (Den(PtNPs)) around 4 nm in size were homogeneously decorated and firmly attached on the SWNHs-ox surface. PtNPs content up to around 40 wt% can be achieved in current research. Three electrode system using dielectrophoretic (DEP) chip was used to analyze the SWNHs-ox-Den(PtNPs) electrocatalytic activity. With the help of G4-NH2, the catalyst possessed high durability since the deposition was still retained on the working electrode even after CV scanning of 250 cycles. More PtNPs content introduced results in higher electrocatalytic activity of catalyst, but the distribution of Den(PtNPs) also played an important role to enhance its electrocatalytic activity. Nevertheless, compact nanocarbon (carbon nanotube, graphene) was preferred for electrocatalyst application.
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