Effects of cobalt salt precursor on the morphology of Co3O4 on CuO NWs. A shell of Co3O4 is formed when cobalt nitrate is used as the cobalt salt precursor. (a) SEM image of CuO/Co3O4 core/shell NWs. The inset shows a single CuO/Co3O4 core/shell NW. (b) TEM image, (c) TEM-EDS spectrum, and (d) HRTEM of the CuO/Co3O4 core/shell NW edge, indicating that the shell is a 9-nm thick polycrystalline Co3O4 film.
Luo et al. Nanoscale Research Letters 2013 8:347 doi:10.1186/1556-276X-8-347