Constructing Built-in Electric Field in Heterogeneous Nanowire Arrays for Efficient Overall Water Electrolysis

Shucong Zhang, Chunhui Tan, Ruipeng Yan, Xifei Zou, Feilong Hu, Yan Mi*, Cheng Yan*, Shenlong Zhao*
Angewandte Chemie, 135(26), e202302795, (2023)


Efficient bifunctional electrocatalysts for hydrogen and oxygen evolution reactions are key to water electrolysis. 

Herein, we report a built-in electric field (BEF) strategy to fabricate heterogeneous nickel phosphide-cobalt nanowire arrays grown on carbon fiber paper (Ni2P-CoCH/CFP) with large work function difference (ΔΦ) as bifunctional electrocatalysts for overall water splitting. Impressively, Ni2P-CoCH/CFP exhibits a remarkable catalytic activity for hydrogen and oxygen evolution reactions to obtain 10 mA cm−2, respectively. 

Moreover, the assembled lab-scale electrolyzer driven by an AAA battery delivers excellent stability after 50 h electrocatalysis with a 100 % faradic efficiency. Computational calculations combining with experiments reveal the interface-induced electric field effect facilitates asymmetrical charge distributions, thereby regulating the adsorption/desorption of the intermediates during reactions. 

This work offers an avenue to rationally design high-performance heterogeneous electrocatalysts.