Graphene as an intermediary for enhancing the electron transfer rate: A free-standing Ni3S2@graphene@Co9S8 electrocatalytic electrode for oxygen evolution reaction
three-dimensional, graphene, Ni3S2@G@Co9S8, oxygen evolution reaction
ABSTRACT A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3S2@graphene@Co9S8 (Ni3S2@G@Co9S8), a sandwich- structured OER electrocatalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER: A low onset overpotential (2 mA·cm−2 at 174 mV), large anode current density (10 mA·cm−2 at an overpotential of 210 mV), low Tafel slope (66 mV·dec−1), and predominant durability of over 96 h (releasing a current density of ~14 mA·cm−2 with a low and constant overpotential of 215 mV) in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.
Tsinghua University Press
Qiuchun Dong,Yizhou Zhang,Ziyang Dai,Peng Wang,Min Zhao,Jinjun Shao,Wei Huang,Xiaochen Dong, Graphene as an intermediary for enhancing the electron transfer rate: A free-standing Ni3S2@graphene@Co9S8 electrocatalytic electrode for oxygen evolution reaction. NanoRes.2018, 11(3): 1389–1398