Shuo Dou, Li Tao,Jia Huo,Shuangyin Wang*, and Liming Dai，Etched and Doped Co9S8/Graphene Hybrid for Oxygen Electrocatalysis
Energy & Environmental Science, 2016, DOI: 10.1039/C6EE00054A
Highly efficient electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been
regarded as the core in a wide range of the renewable energy technologies. Surface engineering on the electrocatalysts is
one of the most popular strategies to improve the catalytic activity. Herein, we, for the first time, designed an advanced bifunctional
electrocatalyst for ORR and OER by simultaneously etching and doping the cobalt sulfides-graphene hybrid with
NH3 plasma. The graphene supported Co9S8 nanoparticles were prepared (denoted as Co9S8/G) first, followed by the NH3
plasma treatment, which could not only lead to nitrogen doping into both Co9S8 and graphene, but also partially etch the
surface of both Co9S8 and graphene. The heteroatom doping could efficiently tune the electronic properties of Co9S8 and
graphene, and the surface etching could expose more active sites for electrocatalysis, which can contribute significantly to
the enhanced electrocatalytic performance for ORR and OER. The electrochemical results revealed that the etched and Ndoped
Co9S8/G shows excellent ORR activity, which is close to the commercial Pt/C catalyst, and great OER activity. The
strategy developed here provided a novel and efficient approach to prepare hybrid bi-functional electrocatalysts for ORR
and OER.
