Enhancing Effect of Fe²⁺ Doping of Ni/NiO Nanocomposite Films on Catalytic Hydrogen Generation

Highly active and stable non-noble metal catalysts are expected to play a critical role in future hydrogen storage and conversion applications. The design of active sites with composite oxides provides a new approach for developing high-performance catalysts. In this study, an Fe-doped Ni/NiO nanocomposite film was constructed on an ionic liquid/water interface to promote hydrogen generation. The optimized Ni/FeNiOx-25 catalyst showed excellent catalytic activity toward ammonia borane hydrolysis, with a turnover frequency of 72.3 min–1. The enhancing effect of Fe2+ doping on Ni/NiO films was confirmed by the improved intrinsic activity and theoretical simulations. Fe ion doping stabilized NiO and prevented NiO from becoming Ni. The interfacial Ni–Fe2+ dual active sites on the FeNiOx and Ni interfaces participated in the targeted adsorption and effective activation of water and NH3BH3 molecules, respectively. The sufficiently exposed plane surface of the nanofilms provided abundant active sites for catalytic reactions. This significant advance will inspire development in the ambient liquid hydrogen storage field.