Graphene/MoS<sub>2</sub>/FeCoNi(OH)<sub>x</sub> and Graphene/MoS<sub>2</sub>/FeCoNiP<sub>x</sub> multilayer-stacked vertical nanosheets on carbon fibers for highly efficient overall water splitting.

Ji, Xixi; Lin, Yanhong; Zeng, Jie; Ren, Zhonghua; Lin, Zijia; Mu, Yongbiao; Qiu, Yejun; Yu, Jie · Nat Commun · 2021

basic_science · Level V

Where this comes from

Abstract

Development of excellent and cheap electrocatalysts for water electrolysis is of great significance for application of hydrogen energy. Here, we show a highly efficient and stable oxygen evolution reaction (OER) catalyst with multilayer-stacked hybrid structure, in which vertical graphene nanosheets (VGSs), MoS<sub>2</sub> nanosheets, and layered FeCoNi hydroxides (FeCoNi(OH)<sub>x</sub>) are successively grown on carbon fibers (CF/VGSs/MoS<sub>2</sub>/FeCoNi(OH)<sub>x</sub>). The catalyst exhibits excellent OER performance with a low overpotential of 225 and 241 mV to attain 500 and 1000 mA cm<sup>-2</sup> and small Tafel slope of 29.2 mV dec<sup>-1</sup>. Theoretical calculation indicates that compositing of FeCoNi(OH)<sub>x</sub> with MoS<sub>2</sub> could generate favorable electronic structure and decrease the OER overpotential, promoting the electrocatalytic activity. An alkaline water electrolyzer is established using CF/VGSs/MoS<sub>2</sub>/FeCoNi(OH)<sub>x</sub> anode for overall water splitting, which generates a current density of 100 mA cm<sup>-2</sup> at 1.59 V with excellent stability over 100 h. Our highly efficient catalysts have great prospect for water electrolysis.