K-Enriched MoO3 Nanobundles: A Layered Structure with High Electric Conductivity

We present a surprisingly simple procedure to synthesize potassium-intercalated MoO3 nanobundles with the integrity of the layered structure remaining intact. While the material displays semiconductor-like behavior, dramatic enhancement of the electric conductivity from 10(-6) S m(-1) of MoO3 to 24 S m(-1) upon potassium uptake was observed. Density functional theory calculations were performed to assist in structural determination and to elucidate the electronic property of the nanobundles. It was found that the K atoms occupy the oxygen vacancy sites in the lattice. The ionization of the K atoms gives rise to the reduction of the adjacent Mo atoms, leading to electron population in the conduction band.