Cost-Effective Alkaline Water Electrolysis Based on Nitrogen- and Phosphorus-Doped Self-Supportive Electrocatalysts.

Water splitting into hydrogen and oxygen in order to store light or electric energy requires efficient electrocatalysts for practical application. Cost-effectiveness, abundance, and efficiency are the major challenges of the electrocatalysts. Herein, this paper reports the use of low-cost 304-type stainless steel mesh as suitable electrocatalysts for splitting of water. The commercial and self-support stainless steel mesh is subjected to exfoliation and heteroatom doping processes. The modified stainless steel electrocatalyst displays higher oxygen evolution reaction property than the commercial IrO2 , and comparable hydrogen evolution reaction property with that of Pt. More importantly, an all-stainless-steel-based alkaline electrolyzer (denoted as NESSP//NESS) is designed for the first time, which possesses outstanding stability along with lower overall voltage than the conventional Pt//IrO2 electrolyzer at increasing current densities. The remarkable electrocatalytic properties of the stainless steel electrode can be attributed to the unique exfoliated-surface morphology, heteroatom doping, and synergistic effect from the uniform distribution of the interconnected elemental compositions. This work creates prospects to the utilization of low-cost, highly active, and ultradurable electrocatalysts for electrochemical energy conversion.