Microstructural Engineering of Heterogeneous P−S−Co Interface for Oxygen and Hydrogen Evolution

Abstract Fabricating and engineering heterointerface was an effective approach to improve electrochemical activity of catalysts through modulating their atomic arrangement and chemical states. Herein, cobalt phosphide and cobalt sulfide (CoP/CoS x ) heterostructure hollow nanocones were fabricated by an in situ ion intercalation template‐assisted method. The microstructure of the heterointerface could be adjusted by changing the molar ratio of S/P. Electrochemical investigation revealed that the disordered structures at the heterointerface could influence the catalytic behavior of active sites. Rationally engineering the disordered structure could improve the electrocatalytic activity for oxygen and hydrogen evolution reactions (OER/HER). The optimized CoP/CoS x heterostructure exhibited favorable catalytic activity for OER, which delivered an overpotential at 10 mA cm −2 of 313 mV and a Tafel slope (93 mV dec −1 ) in alkaline media. Meanwhile, the optimized CoP/CoS x heterostructure also exhibited superior HER performance under acidic condition.