Effect of Few-Layer Ti₃C₂T_<i>x</i> Supported Nano-Ni via Self-Assembly Reduction on Hydrogen Storage Performance of MgH₂

Abstract

For the first time, few-layer Ti₃C₂T_<i>x</i> (FL-Ti₃C₂T_<i>x</i>) supporting highly dispersed nano-Ni particles with an interconnected and interlaced structure was elaborated through a self-assembly reduction process. FL-Ti₃C₂T_<i>x</i> not only acts as a supporting material but also self-assembles with Ni²⁺ ions through the electrostatic interaction, assisting in the reduction of nano-Ni. After ball milling with MgH₂, Ni₃₀/FL-Ti₃C₂T_<i>x</i> (few-layer Ti₃C₂T_<i>x</i> supported 30 wt % nano-Ni via self-assembly reduction) shows superior catalytic activity for MgH₂. For example, MgH₂-5 wt % Ni₃₀/FL-Ti₃C₂T_<i>x</i> can release approximately 5.83 wt % hydrogen within 1800 s at 250 °C and absorb 5 wt % hydrogen within 1700 s at 100 °C. The combined effects of finely dispersed nano-Ni in situ-grown on FL-Ti₃C₂T_<i>x</i>, large specific area of FL-Ti₃C₂T_<i>x</i>, multiple-valence Ti (Ti⁴⁺, Ti³⁺, Ti²⁺, and Ti⁰) derived from FL-Ti₃C₂T_<i>x</i>, and the electronic interaction between Ni and FL-Ti₃C₂T_<i>x</i> can explain the superb hydrogen storage performance. Our results will attract more attention to the elaboration of the metal/FL-Ti₃C₂T_<i>x</i> composite via self-assembly reduction and provide a guideline to design high-efficiency composite catalysts with MXene in hydrogen storage fields.