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

Abstract

Abstract The dandelion‐like Co 3 O 4 /CoWO 4 heterostructure was fabricated for the first time through a two‐step hydrothermal method involving the preparation of urchin‐like Co(CO 3 ) 0.5 (OH) ⋅ 0.11H 2 O at low temperature, as well as its decomposition and an in situ growth of CoWO 4 nanoparticles at relatively high temperature. It is noted that the introduction of Na 2 WO 4 ⋅ 2H 2 O can maintain the morphology stability of precursor and promote the growth of CoWO 4 species, whilst the precursor can be decomposed into the Co 3 O 4 phase at higher hydrothermal temperature. The effects of Na 2 WO 4 ⋅ 2H 2 O on the morphology and electrochemical properties of Co 3 O 4 material were discussed. The electrochemical results showed that the Co 3 O 4 /CoWO 4 hybrid electrode exhibited enhanced specific capacitance, which was 3.4 times larger than that of the pure Co 3 O 4 electrode. The enhanced electrochemical properties were ascribed to the reasonable combination of these two types of electrochemically active materials and its unique architectural feature.