Synthesis of highly electrically conductive and electrochemically stable porous boron-doped carbon microspheres

Abstract

Corrosion resistant carbon with enriched electrical conductivity is advantages for long lasting electrochemical device development. In this study, boron-doped carbon microspheres (BCMS) were prepared by a chemical vapor deposition process from p-xylene and boron trichloride, followed by a mild oxidation step to alter their surface properties and pore structure. XPS study confirmed the formation of the BCMS with a B:C nominal ratio of 1:10.9. Morphological study illustrated the formation of smooth BCMS microspheres with uniform distribution with an average diameter 0.5–1.0 μm. N2 sorption measurements revealed that as synthesized BCMS has a pore structure of less than 2 nm with a maximum distribution around 0.4 nm and a surface area of 213 m2 g−1. Compared to the traditionally used Vulcan XC-72 in polymer electrolyte membrane fuel cells and reversible fuel cells, the BCMS material has similar pore structure and surface area but exhibits higher electrochemical stability. BCMS also exhibits excellent low electrical resistivity (37.2 Ω sq−1) and thermal stability (up to 400 °C) as carbon nanotubes. These superior properties suggest that the BCMS is a very promising candidate as supports for electrocatalysts in electrochemical devices, such as polymer electrolyte membrane fuel cells, reversible fuel cells, lithium-air batteries, etc.