Visible‐Light‐Driven Electrocatalytic Oxygen Evolution Reaction: NiFe<sub>2</sub>O<sub>4</sub>/NiFe–Layered Double Hydroxide Z‐Scheme Heteronanosheet as a Model
Lei Yan, Yanrong Ren, Junling Shen, Haiyan Wang, Jiqiang Ning, Yijun Zhong, Yong Hu
Abstract
A visible‐light‐driven electronic structure regulation strategy is developed to boost the oxygen evolution reaction (OER) activity of the nickel ferrite (NiFe 2 O 4 )/NiFe–layered double hydroxide (LDH) electrocatalyst whose typical Z‐scheme heterostructure makes it an ideal model to explore the mechanisms of photogenerated carriers in the electrocatalytic OER. The oxidation current of the composite increases significantly under visible light irradiation, resulting in a dramatic drop in the overpotential to 180 mV at a current density of 10 mA cm −2 . The Z‐scheme heterostructure with efficient charge separation promotes photogenerated electron transfer from NiFe 2 O 4 to NiFe–LDH, leading to the formation of an electron‐rich Ni and Fe sites in NiFe–LDH and abundant photogenerated holes left in NiFe 2 O 4 , which are responsible for the improved electrocatalytic performance. Herein, the important role of photoactivated electron structure regulation in electrocatalysis is highlighted.