Face-Raised Octahedral Co3O4 Nanocrystals and Their Catalytic Activity in the Selective Oxidation of Alcohols

Face-raised Co 3 O 4 octahedral crystals were successfully constructed through a carbon-assisted method using cellulose as carbon resource and used for a catalyst for selective oxidation of alcohols. The face-raised Co 3 O 4 octahedra are about 200 nm in edge length and assembled to microtubes with a length of ca. 10 μm and a width of 2–3 μm. Our analysis showed that the thermal decomposition and carbonization of cellulose has contributed to the generation of the octahedral structure and the assembled process. Moreover, compared with normal Co 3 O 4 octahedra, the face-raised Co 3 O 4 octahedral crystals have higher remanence and saturation magnetization, which is attributed to their more uniform small grain sizes. In particular, the face-raised Co 3 O 4 octahedra gave both higher activity and higher selectivity than the normal Co 3 O 4 octahedra in the catalytic oxidation reactions of alcohols. More importantly, after eight cycles, the face-raised Co 3 O 4 octahedral crystals still exhibited considerably high catalytic activity, suggesting promising applications in heterocatalysis.