Core-shell NaBH₄ @Ni Nanoarchitectures: A Platform for Tunable Hydrogen Storage.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Complex hydrides are promising for hydrogen storage but often lack reversibility.
• Developing synthetic methods for advanced hydride structures is crucial for practical applications.

Purpose of the Study:

• To design freestanding core-shell sodium borohydride (NaBH₄) @nickel (Ni) nanoarchitectures.
• To correlate hydrogen storage properties with the structure and chemical composition of these nanoarchitectures.

Main Methods:

• Kinetically and thermodynamically controlled nickel shell growth on NaBH₄ particles.
• Near-edge X-ray absorption fine structure (NEXAFS) analysis to determine Ni oxidation states and composition.
• Differential scanning calorimetry (DSC) to measure hydrogen release temperatures.

Main Results:

• Successful synthesis of NaBH₄ @Ni core-shell nanoarchitectures with controlled Ni shell growth.
• Demonstrated tunable hydrogen release properties based on Ni shell composition (Ni⁰/NiₓB<0xE1><0xB5><0xA7> ratio).
• Achieved significantly reduced hydrogen release temperatures (50–95°C) compared to bulk NaBH₄ (>500°C).

Conclusions:

• The core-shell approach offers a viable strategy to enhance the reversibility and performance of complex hydrides for hydrogen storage.
• Control over shell composition is key to destabilizing the hydride system and lowering release temperatures.
• This methodology can be extended to other hydrides, advancing hydrogen storage research.