Compositionally modulated FeMn bimetallic skeletons for highly efficient
overall water splitting
Abstract
Transition metal-based nanomaterials exhibit promising potential as
highly active and low-cost electrocatalyst for alkaline water splitting,
which can be achieved via elaborating compositional modulation and
structural manipulation. This, however, normally involves multiple or
even complex synthetic procedures. Herein, we report a simple one-step
sulfidation of FeMnZn multi–metal skeletons for the preparation of
highly efficient electrocatalysts. The incorporation of Mn and Zn
induced hierarchical nano/micro sheet–to–sheet supported on open
porous skeleton (FeMnZn/Mn-FeS, FMZS2), which not only facilitates
electron/ion transport but also expands the accessible surface.
Meanwhile, the Mn is introduced to optimize the adsorption/desorption
ability of intermediates on the S sites in FeS. The resultant effect
leads to remarkable electrocatalytic performance with good durability.
Notably, the optimized FMZS2 delivers a 20 mA cm–2 at low overpotential
of 118 mV for HER and a 100 mA cm–2 at overpotential of 390 mV for OER,
outperfoming Pt/C and IrO2 catalyst, respectively. Moreover, the
assembled alkaline electrolyzer also has good overall water splitting
capability, which is better than that of the noble metal ones.