Engineering nickel vacancies in NiCo LDH nanoarrays accelerates hydrogen evolution and oxygen evolution reactions.

Exploring efficient bifunctional electrocatalysts is crucial for constructing water splitting systems. In this work, a bifunctional catalyst, NiCo layered double hydroxide (LDH) nanosheets with nickel vacancies, was fabricated by a hydrothermal and chemical etching method, which requires 195 and 227 mV overpotentials for HER and OER to achieve 10 mA cm-2 and exhibited sustained activity for 100 h with almost no degradation. This study provides a new idea for the rational design of efficient non-precious metal catalysts with defects for water splitting.