Ni-N interfacial engineering enables noble-metal-free ammonia photodecomposition

A noble-metal-free Ni-NC@TiO₂ core-shell photocatalyst was developed for efficient hydrogen production from ammonia photodecomposition under visible light without the use of sacrificial agents. In this architecture, Ni nanoparticles are anchored on the nitrogen-doped carbon shell through strong Ni-N interfacial coordination. The conductive NC shell promotes the separation and transport of photogenerated charge carriers, while the Ni sites provide favourable centres for NH₃ adsorption and dehydrogenation. Under visible-light irradiation, Ni-NC@TiO₂ exhibits a hydrogen evolution rate approximately 43 times higher than that of pristine TiO₂. Combined experimental characterizations and DFT calculations reveal that the interfacial Ni-N coupling not only accelerates carrier migration, but also modulates the electronic structure of the Ni sites, thereby lowering the reaction barrier for NH₃ decomposition. Meanwhile, the catalyst shows excellent durability, maintaining stable activity over 40 h without detectable deactivation.