Synthesis of Li-doped Co₃O₄ truncated octahedra with improved performances in CO oxidation and lithium ion batteries

Single-crystalline Li-doped Co₃O₄ truncated octahedra with different doping contents were synthesized by a simple combustion method with the fuel of multi-walled carbon nanotubes (MWCNTs). Controlled experiments showed that the pristine well-defined Co₃O₄ octahedra were obtained with exposed surfaces of {111} planes without lithium doping. In comparison with the octahedra, the truncated Co₃O₄ octahedra were composed of original {111} planes and extra {100} planes. It could be attributable to the selective adsorption of lithium ions on the {100} planes, making these planes with higher surface energy coexist with the crystal faces of {111}. Furthermore, the Li-doped truncated octahedra and undoped octahedra were used as catalysts in CO oxidation and as anode materials for Li-ion batteries (LIBs). The measurements exhibited that the Li-doped octahedra with added {100} crystal faces showed improved catalytic activity and electrochemical property because of the exposure of the higher energy faces of {100} and enhanced conductivity by Li doping.