Metal–Organic Framework Template Derived Porous CoSe₂ Nanosheet Arrays for Energy Conversion and Storage

Porous CoSe₂ on carbon cloth is prepared from a cobalt-based metal organic framework template with etching and selenization reaction, which has both a larger specific surface area and outstanding electrical conductivity. As the catalyst for oxygen evolution reaction, the porous CoSe₂ achieves a lower onset potential of 1.48 V versus the reversible hydrogen electrode (RHE) and a small potential of 1.52 V (vs RHE) at an anodic current density of 10 mA cm^–2. Especially, the linear sweep voltammogram curve of the porous CoSe₂ is in consist with the initial curve after durability test for 24 h. When tested as an electrode for supercapacitor, it can deliver a specific capacitance of 713.9 F g^–1 at current density of 1 mA cm^–2 and exhibit excellent cycling stability in that a capacitance retention of 92.4% can be maintained after 5000 charge–discharge cycles at 5 mA cm^–2. Our work presents a novel strategy for construction of electrochemical electrode.