Electrospun prussian blue analogue derived NiCo@N-doped carbon nanofibers as efficient and highly stable electrocatalysts for neutral overall water splitting

Abstract

Herein, we demonstrate an effective strategy to improve the catalytic stability and efficiency of inexpensive bifunctional electrocatalysts via using electrospun Prussian blue analogue derived NiCo alloy nanoparticles encapsulated in nitrogen-doped carbon nanofibers (NiCo@NC) for neutral overall water splitting. The optimal NiCo@NC-900 exhibits the best electrocatalytic activity toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 M phosphate-buffered saline (PBS, pH 7), respectively. More importantly, a neutral electrolyzer using NiCo@NC-900 as both HER and OER electrodes achieves high stability with over 140 h and requires a low cell voltage of 1.75 V at 10 mA cm−2. The remarkable stability and superior activity origin form the unique hierarchically porous and encapsulated structure, large surface area, abundant exposing active sites, and synergistic effect between the highly catalytic active NiCo alloy nanoparticles and high-conductivity N-doped carbon nanofibers, as demonstrated by the detailed analysis before and after HER and OER testing.