V.G. Zhigalina, O.M. Zhigalina, I.I. Ponomarev, D.N. Khmelenin, D.Yu. Razorenov, Iv.I. Ponomarev, N.A. Kiselev
The structural investigation of Pt-decorated carbon nanofibers (CNFs) with different catalytical coating and treatment techniques was performed by TEM, HRTEM, EDX and SAD methods. Carbon mats obtained by electrospinning using polyacrylonitrile (PAN) were annealed at T = 1200 and 2800 °С and treated by polyvinylpyrrolidone (PVP). Pt decoration of carbon mats was carried out in the solution of hexachloroplatinic acid at a room temperature and a higher temperature of 280 °С. It was shown that the diameter of obtained nanofibers was in the range of 50…400 nm. Without heat treatment the carbon nanofibers structure was amorphous and possessed low thermal stability, but after the annealing process at temperatures higher than 1200 °С the thermal instability disappeared. It was established that Pt nanoparticles had crystallized on the surface of CNFs in fcc lattice. The nanoparticles morphology and dimentions depended on coating technique. Pt decoration process performed at higher temperature leaded to formation of the spherical nanoparticles with average diameter of 3,0 nm. Pt decoration at the room temperature leaded to formation of columnar crystallines with length of 20 nm. The carbonization process of CNFs with surface morphology preservation was stimulated by the PVP treatment and annealing at 1200 °С combined together. The high-temperature annealing at 2800 °С resulted in CNFs carbonization with deformation of the CNFs surface morphology.