Core-Shell Structured NiFeSn@NiFe (Oxy)Hydroxide Nanospheres from an Electrochemical Strategy for Electrocatalytic Oxygen Evolution Reaction.

ABSTRACT: Efficient electrocatalysts for the oxygen evolution reaction (OER) are highly desirable because of the intrinsically sluggish kinetics of OER. Herein, core-shell structured nanospheres of NiFe x Sn@NiFe (oxy)hydroxide (denoted as NiFe x Sn-A) are prepared as active OER catalysts by a facile electrochemical strategy, which includes electrodeposition of NiFe x Sn alloy nanospheres on carbon cloth (CC) and following anodization. The alloy core of NiFe x Sn could promote charge transfer, and the amorphous shell of NiFe (oxy)hydroxide is defect-rich and nanoporous due to the selective electrochemical etching of Sn in alkaline medium. The optimized catalyst of NiFe0.5Sn-A displays a remarkable OER performance with a low overpotential of 260 mV to reach the current density of 10 mA cm-2, a small Tafel slope of 50 mV dec-1, a high turnover frequency of 0.194 s-1 at an overpotential of 300 mV, and a robust durability. Further characterizations indicate that the superior OER performance of the core-shell structured NiFe0.5Sn-A nanospheres might originate from abundant active sites and small charge transfer resistance. This work brings a new perspective to the design and synthesis of core-shell structured nanospheres for electrocatalysis through a facile electrochemical strategy.

SUBMITTER: Chen M 

PROVIDER: S-EPMC7237859 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature