Effect of Boron Doping on the Interlayer Spacing of Graphite

Boron-doped graphite was prepared by the heat treatment of coke using B4C powder as a graphitization catalyst to investigate the effects of the substitutional boron atoms on the interlayer spacing of graphite. Boron atoms can be successfully incorporated into the lattice of graphite by heat treatment, resulting in a reduction in the interlayer spacing of graphite to a value close to that of ideal graphite (0.3354 nm). With an increase in the catalyst mass ratio, the content of substituted boron in the samples increased significantly, causing a decrease in the interlayer spacing of the boron-doped graphite. Density functional theory calculations suggested that the effects of the substitutional boron atoms on the interlayer spacing of the graphite may be attributed to the transfer of pi electrons between layers, the increase in the electrostatic surface potential of the carbon layer due to the electron-deficient nature of boron atoms, and Poisson contraction along the c-axis.

Automated summary

Boron-doped graphite with reduced interlayer spacing was successfully prepared by heat treatment using B4C powder as a catalyst. The increase in catalyst mass ratio resulted in a significant increase in substituted boron content and further reduction in interlayer spacing. Density functional theory calculations suggested that the effects of substitutional boron atoms on interlayer spacing may be attributed to pi electron transfer, increase in electrostatic surface potential, and Poisson contraction along the c-axis.