Ti3C2 MXene supported NiF2 nanoparticles synergistically catalyze efficient hydrogen storage in Mg

Exploiting magnesium-based hydrogen storage materials faces great challenges due to their inherent thermodynamic and kinetic characteristics. However, this issue can be mitigated by employing a catalyst doping modification strategy. In this work, a composite of titanium carbide (Ti 3 C 2 T x MXene)-supported nickel fluoride (NiF 2 ) nanoparticles, known as NiF 2 @Ti 3 C 2 , was fabricated via the hydrothermal approach and utilized to reinforce the hydrogen storage performance of magnesium (Mg). It was shown that NiF 2 @Ti 3 C 2 composites have exceptional catalytic properties for Mg hydrogen storage. The Mg–NiF 2 @Ti 3 C 2 composite, containing 5 wt% of NiF 2 @Ti 3 C 2 , released 3.46 wt% of hydrogen at 300 °C, while pure Mg produced essentially little hydrogen in identical conditions. Additionally, there was a decrease in the activation energy of hydrogen desorption from 135.4 to 77.65 kJ mol −1 . Moreover, the composite offered excellent stability and reversible performance, achieving 95.8% capacity retention after 10 consecutive testing cycles. During the hydrogen uptake and release process, the NiF 2 @Ti 3 C 2 composite interacted with Mg/MgH 2 to produce the metals Ti 0 , MgF 2 , and Mg 2 Ni/Mg 2 NiH 4 , which acted as active species to boost the hydrogen storage performance of Mg.