Stable overall water splitting in an asymmetric acid/alkaline electrolyzer comprising a bipolar membrane sandwiched by bifunctional cobalt‐nickel phosphide nanowire electrodes

• DOI: 10.1002/cey2.56
• Publication Date: 2020-06-08T14:51:29Z
• Authors: Junyuan Xu; Isilda Amorim; Yue Li; Junjie Li; Zhipeng Yu; Bingsen Zhang; Ana Araujo; Nan Zhang; Lifeng Liu
• Keywords: Alkaline water electrolysis; Oxygen evolution; Phosphide; Alkaline fuel cell; Electrolysis of water

Abstract Water splitting has been proposed to be a promising approach producing clean hydrogen fuel. The two half‐reactions of water splitting, that is, the evolution reaction (HER) and oxygen (OER), take place kinetically fast in solutions with completely different pH values. Enabling HER OER simultaneously occur under favorable conditions while using exclusively low‐cost, earth‐abundant electrocatalysts is highly desirable but remains challenge. Herein, we demonstrate bipolar membrane (BPM) can accomplish strongly acidic solution basic solution, bifunctional self‐supported cobalt‐nickel phosphide nanowire electrodes catalyze both reactions. Such asymmetric acid/alkaline electrolysis achieved at 1.567 V deliver current density 10 mA/cm 2 ca. 100% Faradaic efficiency. Moreover, an “irregular” BPM unintentional crossover voltage needed afford reduced 0.847 V, due assistance electrochemical neutralization between acid alkaline. Furthermore, show BPM‐based accomplished circulated single‐cell electrolyzer delivering 1.550 very stably for least 25 hours, enabled by solar panel operating 0.908 (@13 ), BPM. alternative conventional proton anion exchange electrolysis.