Hydrothermal synthesis of Co3O4 nanorods on nickel foil

• The facile hydrothermal method for the synthesis of Co3O4 nanorods (NRs) has been reported.
• The Co3O4 NRs initially grouped into bundle structure and then formed spark.
• The length of Co3O4 NRs is several micrometers up to tens of micrometers with diameter of 1 μm.
• The NRs are stacked layer-by-layer from single grains in 50–200 nm.

Co3O4 nanorods (NRs) were successfully synthesized on nickel foil by a facile hydrothermal reaction. The X-ray diffraction (XRD) investigation confirms the formation of spinel Co3O4 phase. Owing to the mismatch between Co3O4 and substrate, the Co3O4 NRs initially grouped into bundle structure and then formed dispersed NRs. The length of Co3O4 NRs varies from several micrometers up to tens of micrometers with uniform diameter of about 1 μm. Transmission electron microscopy (TEM) characterization demonstrated that the NRs are stacked layer-by-layer from single grains in 50–200 nm. This facile hydrothermal method for preparation of Co3O4 NRs is significant in the synthesis and future applications of one-dimensional (1D) nanostructures.