Interface effect in sandwich like Ni/Ti3C2 catalysts on hydrogen storage performance of MgH2

Abstract Sandwich like Ni/Ti3C2 catalysts with interfacial differences were controllably fabricated via modified wet chemical method. Through changing the solvents (water, ethylene glycol and an equal mixture of the two), Ni nanoparticles with different morphologies (size and dispersibility) on Ti3C2 matrix can be attained, leading to different interfaces between Ni nanoparticles and Ti3C2 matrix. After ball milling with MgH2, the Ni/Ti3C2 catalyst prepared from the mixed solvent (Ni/Ti3C2-WE) shows the best catalytic activity, which exhibits the minimum Ni particle size and crystallite size, and the best dispersion of Ni nanoparticles on Ti3C2 matrix. The electronic interaction brought by the rich interfaces and contacts between Ni nanoparticles and Ti3C2 matrix can dramatically improve the hydrogen storage performance of MgH2. In addition, electron transfers in multiple valence Ti (Ti0, Ti2+, Ti3+, Ti4+) and the unique structure of sandwich like Ni/Ti3C2 catalyst are also deemed as very crucial factors for enhancing catalytic activity of Ni/Ti3C2-WE. This research has shown the importance of the interfacial interaction between multiphase of catalysts on improving hydrogen storage performance of Mg-based materials experimentally and theoretically, providing a guideline to elaborate high efficiency multiphase catalysts.