ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of heat treatment on the morphology of carbon fibers doped with Co₂p nanoparticles

M. Stelmakova, M. Streckova, R. Orinakova, A. Guboova, M. Balaz, V. Girman, E. Mudra, C. Bera, and M. Batkova

Institute of Materials Research, Slovak Academy of Sciences, Kosice, Slovak Republic

E-mail: mstreckova@saske.sk

Received: 30 April 2021  Accepted: 22 September 2021

Abstract:

Abstract

Carbon fibers (CFs) decorated by Co₂P nanoparticles and carbon nanotubes were prepared via needle-less electrospinning technique. Formation of catalytically active Co₂P nanoparticles and growth of carbon nanotubes were monitored in open and closed sintering environment at different sintering exposure times. Higher porosity, important in the catalytic reaction for easier penetration of electrolyte into the CFs, was achieved by mixing two immiscible polymers with natrium dodecyl sulfate and subsequent heat treatment process. Structure and morphology of the prepared modified carbon fibers were characterized by XRD, SEM and TEM. The time of heat exposure at the sintering temperature of 1200 °C and closure of the sintering space showed distinct effect on the growth and shape of carbon nanotubes. SEM and Raman spectroscopy revealed that closure of the system led to the formation of carbon nanotubes with smaller diameters and less structural disorder. Comparing of as-prepared CFs revealed that CFs with Co₂P sintered in the closed system exhibited the best electrocatalytic activity for hydrogen evolution reaction due to lower overpotential and smaller Tafel slope in acidic solution.

Graphic abstract

Keywords: Carbon fibers; Cobalt phosphide; Heat treatment; HER

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01897-0

Chemical Papers 76 (2) 855–867 (2022)