Nitrogen–Doped Carbon Nanotube–Supported Ni ₃ Se ₄ –CeO ₂ Heterojunctions With Multi–Orbital Hybr

ABSTRACT

Engineering of the catalyst interface and modulation of transition–metal d–band play critical roles in the electrocatalytic hydrogen evolution reaction (HER). Herein, a synthetic strategy is developed to fabricate nitrogen‐doped carbon nanotubes (N–CNTs)–supported Ni ₃ Se ₄ –CeO ₂ heterojunction catalysts through a facile chemical vapor deposition (CVD) process coupled with selenization. The heterojunction catalysts show excellent catalytic activity and stability for HER. Density functional theory (DFT) calculations reveal that Se modifies the electronic structure of Ni, CeO ₂ regulates the interfacial charge distribution, and a multi–orbital coupling effect arises among the components. These synergistic effects collectively elevate the d–band center, thereby optimizing the free energy of the key adsorbed hydrogen intermediate (Δ G _H* ) in HER. Benefiting from the synergies between interface engineering and multi–orbital hybridization, the optimized Ni ₃ Se ₄ –CeO ₂ heterojunction delivers a low overpotential of 180 mV at 100 mA cm ⁻² , with a Tafel slope of 83.6 mV dec ⁻¹ . The N–CNTs substrate further reduces charge–transfer resistance, thus promoting HER performance. Moreover, the confinement effect provided by cellulose acetate (CA) and the hydrogen–bonding network formed within the cotton substrate ensure outstanding long–term durability, as evidenced by sustained catalytic activity after 100 h of continuous operation at 100 mA cm ⁻² . This work will offer a promising pathway toward the development of efficient heterojunction catalysts for HER via modulation of their electronic structure and interface.