Interfaces Engineering of Ultrafine Ni@Ni₂P/C Core-Shell Heterostructure for High Yield Hydrogen Peroxide Electrosynthesis

Developing cost-effective and sustainable catalysts with exceptional activity and selectivity is essential for the practical implementation of on-site H₂O₂ electrosynthesis, yet it remains a formidable challenge. Metal phosphide core-shell heterostructures anchored in carbon nanosheets (denoted as Ni@Ni₂P/C NSs) are designed and synthesized via carbonization and phosphidation of the 2D Ni-BDC precursor. This core-shell nanostructure provides more accessible active sites and enhanced durability, while the 2D carbon nanosheet substrate prevents heterostructure aggregation and facilitates mass transfer. Theoretical calculations further reveal that the Ni/Ni₂P heterostructure-induced optimization of geometric and electronic structures enables the favored adsorption of OOH^* intermediate. All these features endow the Ni@Ni₂P/C NSs with remarkable performance in 2e ORR for H₂O₂ synthesis, achieving a top yield rate of 95.6 mg L^-1 h^-1 with both selectivity and Faradaic efficiency exceeding 90% under a wide range of applied potentials. Furthermore, when utilized as the anode of an assembled gas diffusion electrode (GDE) device, the Ni@Ni₂P/C NSs achieve in situ H₂O₂ production with excellent long-term durability (>32 h). Evidently, this work provides a unique insight into the origin of 2e ORR and proposes optimization of H₂O₂ production through nano-interface manipulation.