Formation of Dandelion-Like Co3O4/CoWO4 Heterojunctions for Enhanced Supercapacitive Performance

The dandelion-like Co3O4/CoWO4 heterostructure was fabricated for the first time through a two-step hydrothermal method involving the preparation of urchin-like Co(CO3) 0.5( OH)center dot 0.11H(2)O at low temperature, as well as its decomposition and an in situ growth of CoWO4 nanoparticles at relatively high temperature. It is noted that the introduction of Na2WO4 center dot 2H(2)O can maintain the morphology stability of precursor and promote the growth of CoWO4 species, whilst the precursor can be decomposed into the Co3O4 phase at higher hydrothermal temperature. The effects of Na2WO4 center dot 2H(2)O on the morphology and electrochemical properties of Co3O4 material were discussed. The electrochemical results showed that the Co3O4/CoWO4 hybrid electrode exhibited enhanced specific capacitance, which was 3.4 times larger than that of the pure Co3O4 electrode. The enhanced electrochemical properties were ascribed to the reasonable combination of these two types of electrochemically active materials and its unique architectural feature.