Electronic Structure Modulation of Ni 2 P Nanospheres via Interfacial Control With Lattice‐Expanded MoS 2 Nanosheets for Enhanced Hydrogen Evolution
Hyungu Han, Won Jun Kang, Duong Nguyen Nguyen, Chandan Chandru Gudal, Somi Lee, Taekyung Kim, Chan‐Hwa Chung, Jung Kyu KimABSTRACT
The development of cost‐effective and durable electrocatalysts is a prerequisite for scalable hydrogen production via water electrolysis. In this context, modulating the electronic structure of transition‐metal phosphide electrocatalysts via interfacial engineering with transition‐metal chalcogenides has emerged as a compelling strategy to accelerate the hydrogen evolution reaction. Herein, we report an ultrasonication‐assisted synthesis of ultrathin sub‐20‐nm MoS 2 intimately integrated with Ni 2 P nanoparticles (R‐MoS 2 @Ni 2 P). In R‐MoS 2 @Ni 2 P, the unique heterointerface configuration induces a bending‐induced lattice expansion in ultrathin MoS 2 and modulates the electronic structure of Ni 2 P, facilitating interfacial charge redistribution for efficient HER. XPS analysis reveals that electrons are partially transferred from Ni 2 P to ultrathin MoS 2 . Furthermore, density functional theory calculations revealed that tensile strain in the O‐MoS 2 results in a downshift of the d‐band center and an optimized hydrogen adsorption free energy (∆G H* ). Consequently, the as‐prepared R‐MoS 2 @Ni 2 P exhibits significantly enhanced HER activity and long‐term stability in both half‐cell measurements and a PEMWE system compared with pristine Ni 2 P. This study demonstrates that interfacial engineering with ultrathin MoS 2 nanosheets is an effective strategy to optimize the electronic properties of active Ni 2 P species, offering a promising design framework for advanced energy‐conversion catalysts.