Constructing a Built-in Electric Field of Ni₂P-CeO₂ Heterostructure for Efficient Hydrogen Evolution Reaction

In this study, we utilized a green method to prepare the material precursor (CC/CA/Ni²⁺-Ce³⁺) by using commercial cotton cloth (CC) and cellulose acetate (CA) as sources, leveraging the synergistic chelation effect of cellulose acetate and cotton cloth to coordinate nickel and cerium ions. Subsequently, precursor CF-C/Ni-CeO₂ was obtained through high-temperature pyrolysis, followed by phosphidation to form the CF-C/Ni₂P-CeO₂ heterostructure. Within this structure, CeO₂ acts as an "electron acceptor", enabling electron transfer from Ni₂P to CeO₂ and promoting rapid charge redistribution through an oxygen vacancy-mediated electron-ion cooperative transport mechanism. This process optimizes the adsorption free energy of hydrogen intermediates (ΔG_H*) during the hydrogen evolution reaction (HER). This synergistic effect of dual active sites enables the CF-C/Ni₂P-CeO₂-2 electrode with outstanding HER catalytic performance under alkaline conditions, achieving a current density of 10 mA cm^-2 at an overpotential of only 102 mV and 100 mA cm^-2 at 234 mV, while maintaining stability for more than 50 h at a high current of approximately 100 mA cm^-2.