Graphene/MoS₂/FeCoNi(OH)_x and Graphene/MoS₂/FeCoNiP_x multilayer-stacked vertical nanosheets on carbon fibers for highly efficient overall water splitting.

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), MoS₂ nanosheets, and layered FeCoNi hydroxides (FeCoNi(OH)_x) are successively grown on carbon fibers (CF/VGSs/MoS₂/FeCoNi(OH)_x). The catalyst exhibits excellent OER performance with a low overpotential of 225 and 241 mV to attain 500 and 1000 mA cm^-2 and small Tafel slope of 29.2 mV dec^-1. Theoretical calculation indicates that compositing of FeCoNi(OH)_x with MoS₂ could generate favorable electronic structure and decrease the OER overpotential, promoting the electrocatalytic activity. An alkaline water electrolyzer is established using CF/VGSs/MoS₂/FeCoNi(OH)_x anode for overall water splitting, which generates a current density of 100 mA cm^-2 at 1.59 V with excellent stability over 100 h. Our highly efficient catalysts have great prospect for water electrolysis.

SUBMITTER: Ji X 

PROVIDER: S-EPMC7925597 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature