Facile metal-free reduction-based synthesis of pristine and cation-doped conductive mayenite.

In the present study we synthesized conductive nanoscale [CaAlO](4e) (hereafter denoted as CA:e) material, and reduced graphene oxide (rGO) was produced, which was unexpected; graphene oxide was removed after melting the sample. The conductivity of CA:e composites synthesized at 1550 °C was 1.25 S cm, and the electron concentration was 5.5 × 10 cm. The estimated BET specific surface area of the highly conductive sample was 20 m g. Pristine CA:e electride was obtained by melting the composite powder, but the nano size of CA:e particles could not be preserved; the value of conductivity was ∼28 S cm, electron concentration was ∼1.9 × 10 cm, and mass density was 93%. For CA V :e, where = 0.25 to 1, the conductivity improved to a maximum value of 40 S cm, and the electron density improved to ∼2.2 × 10 cm; this enhancement in conductivity was also proposed by a theoretical study but lacked any associated experimental support.