Robust NiCoP@FeP derived from Prussian blue analog for efficient overall water splitting

Abstract

The design of efficient, stable, and non-noble metal-based bifunctional electrocatalysts remains a great challenge. The synergistic effect can adjust the local electronic structure to improve the catalytic performance. In this work, an Fe Prussian blue analog was grown in situ on the surface of NiCo precursor nanoneedles at room temperature, and then one-dimensional unique NiCoP@FeP hierarchical nanocomposites were constructed by subsequent phosphating. The optimized NiCoP@FeP with strong electronic interactions showed a low overpotential of 268 mV at 50 mA cm⁻² for the OER and 75 mV at 10 mA cm⁻² for the HER. Moreover, for water splitting, the bifunctional catalyst required only a low cell voltage of 1.58 V to reach a current density of 10 mA cm⁻² with excellent durability. This work provides a new synthesis strategy to construct non-noble metal heterostructure bifunctional electrocatalysts using the Prussian blue analog in the future.