p–d Orbitals Coupling Heterosites of Ni 2 P/NiFe‐LDH Interface Enable O─H Cleavage for Water Splitting

• Published in: Advanced functional materials 2024-10, Vol.34 (40)
• Main Authors: Ge, Zi‐Qi, Li, Jingwei, Zhang, Hui‐Jian, Liu, Chunbo, Che, Guangbo, Liu, Zhao‐Qing
• Format: Article
• Language: English
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202411024

Electrocatalytic water splitting for hydrogen production still faces a bottleneck due to sluggish reactive kinetics and high reactive energy barriers. Herein, p–d orbital coupling P–Fe heterosites are constructed at Ni 2 P–FeNi‐LDH interfaces to enhance the O─H bond cleavage of reaction intermediates H 2 O* and OH* for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The Ni 2 P/NiFe‐LDH heterostructure shows superior HER and OER activities for alkaline water splitting with overpotentials of 230 and 270 mV at 100 mA cm −2 , respectively, and even exhibits high activity for electrocatalytic alkaline seawater splitting. The interaction of P 2p and Fe 3d orbitals at Ni 2 P–FeNi‐LDH interfaces upshifts the d‐band center of Fe and downshifts the p‐band center of P. This finding not only facilitates the dissociation of O─H bonds in H 2 O and promotes the Volmer–Heyrovsky step for HER, but also reduces the energy barrier for the rate‐determining step of OER from OH* to O* transition. This work proposes a new approach to constructing p–d heterosites at heterojunctions to facilitate reactive kinetics and reduce the energy barrier for electrocatalysis.