Effects of solvent on the morphology of Co3O4 on CuO NWs. Schematic drawing of the sol-flame method (a), for which bare CuO NWs (b) are dip-coated with a cobalt precursor containing cobalt salt and solvent and air dried (c), followed by a rapid flame annealing process to form Co3O4-decorated CuO NW heterostructure. SEM image of Co3O4-decorated CuO NWs prepared by the sol-flame method with different air-drying conditions: 25°C for 0.4 h (d), 25°C for 22 h (e), 130°C for 1.5 h (f), and first dried at 130°C for 1.5 h, then reapplied acetic acid and dried at 25°C for 0.4 h (g). Extensive drying by increasing duration or temperature inhibits the formation of the Co3O4 NP-chain morphology.
Luo et al. Nanoscale Research Letters 2013 8:347 doi:10.1186/1556-276X-8-347