Synthesis of carbon nanofibers by thermal conversion of the molecular precursor 5,6;11,12-di-o-phenylenetetracene and its application in a chemiresistive gas sensor

Abstract

Carbon nanofibers with an amorphous solid structure have been synthesized by thermal conversion of the polycyclic aromatic hydrocarbon 5,6;11,12-di-o-phenylenetetracene (DOPT) at 1000 C on various substrates. Rapid annealing of DOPT on copper foil, SiO 2 /Si wafer and a SiO 2 /Si wafer coated with a 20 nm thick layer of Pt/Pd resulted in growth of carbon nanofibers. The most effective synthesis of these fibers was realized on the latter substrate. The Pt/Pd layer segregates by dewetting under thermal treatment and forms metallic nanoparticles on which dense networks of amorphous carbon nanofibers were prepared and these were successfully applied in chemiresistor gas sensor applications for detection of toxic gases, e.g. nitrogen dioxide, ammonia and sulfur dioxide. Using an analyte concentration of parts per million, the nanofibers show a very good response towards NO 2 and SO 2 , whereas exposure to ammonia resulted only in negligible, minor changes in the electrical resistance of the sensor.

Strategies in Precursors and Post Treatments to Strengthen Carbon Nanofibers

“…There are also other strategies to synthesize CNFs, such as the thermal conversion of hydrocarbons on various substrates [77,78], electrospinning with coaxial nozzles [79], and template synthesis in porous substrate [80][81][82]. These methods are often used to prepare CNFs with special structures and assembly forms.…”

“…These methods are often used to prepare CNFs with special structures and assembly forms. For example, Krauß et al [77] reported amorphous CNFs by thermal transformation of polycyclic aromatic hydrocarbon 5,6;11,12-di-o-phenylenetetracene, and Wang et al [82] synthesized CNFs containing linear mesocage arrays where the cages were formed via the evaporation of solvent.…”