Few-layer MXene Ti3C2Tx supported Ni@C nanoflakes as a catalyst for hydrogen desorption of MgH2

Abstract

Slow hydrogen desorption kinetics and poor cycle durability of MgH₂ still remain as challenges for practical applications. In this work, a new approach is proposed to synthesize few-layer MXene Ti₃C₂T_x supported Ni@C nanoflakes (Ni@C/FL-Ti₃C₂T_x), which can serve as a highly efficient catalyst for hydrogen desorption of MgH₂. After ball milling under a 4 MPa hydrogen atmosphere for 15 hours, the MgH₂–10 wt% Ni@C/FL-Ti₃C₂T_x composite exhibits superior hydrogen desorption kinetics and excellent cycling stability. Further investigation reveals that the enhancement of hydrogen storage properties is attributed to the in situ formed Mg₂NiH₄ and metallic Ti nanoparticles with a fine size and high dispersity as well as the FL-Ti₃C₂T_x nanosheets themselves. This work not only reports an effective strategy for improving the hydrogen storage properties of Mg-based materials but provides new insights into the underlying mechanism for optimizing the properties.