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.