Assembling Co9S8 nanoflakes on Co3O4 nanowires as advanced core/shell electrocatalysts for oxygen evolution reaction

摘要

Rational design of advanced cost-effective electrocatalysts is vital for the development of water electrolysis. Herein, we report a novel binder-free efficient Co9S8@Co3O4 core/shell electrocatalysts for oxygen evolution reaction（OER） via a combined hydrothermal-sulfurization method. The sulfurized net-like Co9S8 nanoflakes are strongly anchored on the Co3O4 nanowire core forming self-supported binder-free core/shell electrocatalysts. Positive advantages including larger active surface area of Co9S8 nanoflakes,and reinforced structural stability are achieved in the Co9S8@Co3O4 core/shell arrays. The OER performances of the Co9S8@Co3O4 core/shell arrays are thoroughly tested and enhanced electrocatalytic performance with lower over-potential(260 m V at 20 m A cm-2) and smaller Tafel slopes（56 mV dec-1） as well as long-term durability are demonstrated in alkaline medium. Our proposed core/shell smart design may provide a new way to construct other advanced binder-free electrocatalysts for applications in electrochemical catalysis.