A regulation strategy using trace copper boosting electrocatalytic activity of bifunctional metallic dihydroxy in hydrogen evolution and methanol oxidation

Discovering efficient and promising bifunctional electrocatalysts is pivotal for a sustainable energy system. Herein, we propose a simple and efficiency strategy to construct a highly efficient flower-like NiCo dihydroxy catalyst containing trace amounts of Cu2+. Due to the incorporation of Cu2+, low-valence Niδ+ (0 < δ < 2) and more high-valence Co3+ are formed. This indicates that part of the Co electrons are transferred to the surrounding Ni, thereby achieving electron enrichment of Ni sites and improving HER activity. The Ni2Co1Cu LDH/NF 0.008 only needs overpotentials of 19 mV and 113 mV to reach 10 mA cm−2 and 50 mA cm−2 for HER and has long-term stability, and at 1.35 V to reach 10 mA cm−2 for MOR. The catalyst can reach a cell voltage of 1.47 V for MOR and HER bifunctional catalysis. This work provides a novel strategy to fabric highly efficient dual-functional electrocatalysts of transition metal hydroxides.