Electron modulation strategy of heterogeneous Ni2P/FeP coupled with CeO2 for efficient overall water splitting

Abstract

Interface engineering presents a promising avenue for elucidating the electronic structure of an electrocatalyst to enhance the ad/desorption process of intermediate substances (H2O*, H*, OH*). This study used a strategy guided by interface engineering optimization to design a heterostructure electrocatalyst (CeO2-Ni2P/FeP/NF). In alkaline media, heterostructure electrocatalyst requires only 103 mV and 189 mV to drive the HER and OER at a current density of 10 mA·cm−2. As a dual-function electrode, CeO2-Ni2P/FeP/NF electrocatalysts require only 1.53, 1.76, and 1.85 V cell voltage to provide 10, 50, and 100 mA·cm−2 current densities. Experiments and DFT calculations reveal that CeO2 can promote electronic reconstruction at heterogeneous interfaces, enhancing the activity of Ni, Fe, and P sites. More importantly, the CeO2-Ni2P/FeP/NF heterojunction exhibits great synergistic effects, optimizing the ad/desorption of H2O* and H*, consequently inducing a substantial increase in the electronic energy at the Fermi level. This work presents a promising electronic structure adjustment strategy to fabricate highly active and durable electrocatalysts for efficient energy conversion.