Heterogeneous Cu incorporated into Ni6Fe2-LDH/rGO induces spin exchange interaction to enhance alkaline hydrogen evolution.

The efficiency of hydrogen evolution reaction (HER) takes an important influence on electrochemical water electrolysis, yet it still delivers sluggish kinetics mainly due to the high kinetic energy barriers. Herein, Cu 1 Ni 5 Fe 2 -Layered double hydroxides/reduced graphene oxide (denoted as Cu 1 Ni 5 Fe 2 -LDHs/rGO) with heterogeneous Cu atoms incorporated into Ni 6 Fe 2 -LDHs/rGO is constructed through a hydrothermal method and doping strategy in this works, wherein the subtle lattice distortion is availably regulated and optimized by Cu2+ Jahn-Teller effect, offering more active sites for HER. As benefits of the subtle lattice distortion and the spin exchange interaction, Cu 1 Ni 5 Fe 2 -LDHs/rGO displays ferromagnetism at room temperature and shows superior alkaline HER properties with a relatively low overpotentials of 50 mV at 10 mA cm−2 in 1.0 M KOH. The low Tafel slope of 38 mV dec−1 implies Cu 1 Ni 5 Fe 2 -LDHs/rGO owns an ultra-fast HER kinetic. This study can offer a new strategy to construct high efficient HER catalysts based on transition metal NiFe-LDHs. [Display omitted] • A new preparation, it is first time to fabricate Cu 1 Ni 5 Fe 2 -LDHs/rGO. • The subtle lattice distortion is optimized by the Cu2+ Jahn-Teller effect. • Cu 1 Ni 5 Fe 2 -LDHs/rGO displays ferromagnetism at room temperature. • Cu 1 Ni 5 Fe 2 -LDHs/rGO shows an ultra-fast HER kinetic with a low Tafel slope of 38 mV dec−1. [ABSTRACT FROM AUTHOR]