Cobalt phosphide nanoarrays on a borate-modified nickel foam substrate as an efficient dual-electrocatalyst for overall water splitting

• Published in: Journal of colloid and interface science Vol. 683; no. Pt 1; pp. 509 - 520
• Main Authors: Zhou, Ruijuan, Zhang, Jinghao, Long, Junxi, Li, Lingfeng, Ye, Qinglan, Xu, Xuetang, Wang, Fan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2025
• Subjects: borates; catalysts; catalytic activity; cobalt; Cobalt phosphide; durability; electric field; electric potential difference; electrodes; foams; hydrogen; hydrogen production; Interfacial layer; nanowires; nickel; Nickel borate; Overall water splitting; oxygen production; phosphides; renewable energy sources; synergism; Interfacial layer; Overall water splitting; Cobalt phosphide; Nickel borate
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/j.jcis.2024.12.046

[Display omitted] Developing efficient non-noble metal dual-functional electrocatalysts for overall water splitting is essential for the production of green hydrogen. Given the significant advantages of self-supporting electrodes, regulating the growth of self-supporting nanoarrays on a conductive substrate is conducive to improving the electrocatalytic activity. In this work, aligned cobalt phosphide (CoP) nanowire arrays grown on borate-modified Ni foam substrate (CoP/R-NF) were utilized as a bifunctional electrocatalyst for both hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) in alkaline solution. The borate interfacial layer regulated the growth behavior of CoP nanowires, promoting a tip-enhanced electric field effect, facilitating an enhanced bimetallic synergistic effect. The CoP/R-NF electrode showed substantial catalytic activity for HER (η10 = 35 mV, 70 mV dec-1) and OER (241 mV, 32 mV dec-1). Moreover, a low cell voltage of 1.50 V to drive 10 mA cm−2 current density for overall water-splitting was achieved in an alkaline water electrolyzer, with long-term durability of 200 h at 100 mA cm−2, indicating the potential application of CoP/R-NF as a bifunctional catalyst for clean and renewable energy utilization. Such a synthetic strategy could pave the way for the development of non-noble bifunctional electrocatalysts for comprehensive water splitting.