NaBH4 induces a high ratio of Ni3+/Ni2+ boosting OER activity of the NiFe LDH electrocatalyst

• DOI: 10.1039/d0ra06617f
• Publication Date: 2020-09-10T10:44:25Z
• Authors: Yaqiong Wang; Shi Tao; He Lin; Shaobo Han; Wenhua Zhong; Yangshan Xie; Jue Hu; Shihe Yang
• Keywords: Oxygen evolution; Overpotential

Electrochemical water splitting is a promising way to produce hydrogen gas, but the sluggish kinetics of oxygen evolution reaction (OER) extremely restrict overall conversion efficiency splitting. Transition metal based LDHs (TM LDHs) are one most effective non-noble OER catalysts and have attracted wide interest, especially nickel-iron LDH (NiFe LDH). The high valence Ni3+ species with large coordination number play vital role in catalysis. Herein, we report on surprising discovery that between NiFe NaBH4 multi-hydrides induces vacancy formation around Fe3+ enrichment Ni3+, crucially activating performance. ratio Ni3+/Ni2+ found be closely tied performance, nicely accounting for leading ions octahedral sites electrocatalysis. Significantly, treated directly nickel foam (NF), denoted as NaBH4-NiFe LDH@NF exhibited an outstanding performance overpotential only 310 mV at 100 mA cm-2, Tafel slope 47 dec-1. For series TM studied different combinations, ion positively related