Highly Enhanced OER Activity of Amorphous Co3O4 via Fabricating Hybrid Amorphous‐Crystalline Gold Nanostructures

Abstract Hybrid nanostructures of amorphous cobalt oxide (Co 3 O 4 ) and crystalline gold nanoparticles (AuNPs) showed strongly enhanced OER activity compared to pure amorphous Co 3 O 4 . Particularly, gold nanorods (Au NRs) integrated amorphous Co 3 O 4 nanostructures (aCo 3 O 4 /Au NRs) required significantly low overpotential (225 mV) to produce geometric current density and needed 336 and 398 mV for achieving current density of 100 and 400 mA/cm 2 , respectively. Further, aCo 3 O 4 /Au NRs displayed good stability over 40 h at 336 mV.