Trace Iridium Engineering on Nickel Hydroxide Nanosheets as High-active Catalyst for Overall Water Splitting

Designing cost-effective electrocatalysts for electrochemical water splitting to generate the hydrogen energy as a future energy source is pivotal. An excellent catalyst should show high catalytic activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under different pH conditions. Here, we highlighted a high-efficient catalyst of Ir-doped Ni(OH)(2)nanosheets grown on Ni foam (Ir-Ni(OH)(2)/NF) as a high-efficient catalyst for overall water splitting in both alkaline and neutral conditions via a simple one-step hydrothermal strategy. The optimized Ir-3-Ni(OH)(2)/NF shows superior HER and OER activity in neutral and alkaline electrolytes. The doped Ir ions can not only serve as catalytic sites for water dissociation, but also decrease the charge density of the adjacent bridge oxygen to facilitate HER kinetics. As a result, Ir-3-Ni(OH)(2)/NF electrolyzer exhibits superior performance of a small potential of 1.64 V under neutral condition, which is obviously lower than that of a string of recently reported neutral-pH electrocatalysts.