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

In the present study we synthesized conductive nanoscale [Ca(24)Al(28)O(64)](4+)(4e(−)) (hereafter denoted as C(12)A(7):e(−)) material, and reduced graphene oxide (rGO) was produced, which was unexpected; graphene oxide was removed after melting the sample. The conductivity of C(12)A(7):e(−) composites synthesized at 1550 °C was 1.25 S cm(−1), and the electron concentration was 5.5 × 10(19) cm(−3). The estimated BET specific surface area of the highly conductive sample was 20 m(2) g(−1). Pristine C(12)A(7):e(−) electride was obtained by melting the composite powder, but the nano size of C(12)A(7):e(−) particles could not be preserved; the value of conductivity was ∼28 S cm(−1), electron concentration was ∼1.9 × 10(21) cm(−3), and mass density was 93%. For C(12)A(7−x)V(x):e(−), where x = 0.25 to 1, the conductivity improved to a maximum value of 40 S cm(−1), and the electron density improved to ∼2.2 × 10(21) cm(−3); this enhancement in conductivity was also proposed by a theoretical study but lacked any associated experimental support.