Constructing 3D hierarchical MOFs nanospheres for oxygen evolution from high-throughput calculations

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Outstanding electrochemical performance in oxygen evolution reactions (OER) requires advanced nanostructured materials.
• 3D hierarchical nanospheres composed of 2D bimetal metal-organic framework (MOF) nanosheets are promising for OER catalysis.

Purpose of the Study:

• To synthesize and characterize novel 3D hierarchical nanospheres from Ni-V bimetal MOFs (NiV-MNs).
• To investigate the OER catalytic performance of NiV-MNs and understand the structure-activity relationship.
• To report the first synthesis of V-based ultrathin 2D MOFs.

Main Methods:

• High-throughput density-functional theory (DFT) calculations to screen central ions.
• One-step solvothermal synthesis of Ni-V bimetal MOFs nanospheres (NiV-MNs).
• Electrochemical testing in alkaline conditions to evaluate OER performance.
• DFT calculations to analyze catalytic mechanisms and intermediate binding energies.

Main Results:

• NiV-MNs assembled from ultrathin 2D MOF nanosheets were successfully synthesized.
• Ni₁V₁-MNs demonstrated the highest catalytic activity for OER.
• Ni₁V₁-MNs achieved a current density of 50 mA·cm^-2 at an over-potential of 370 mV with excellent long-term stability (>10000 s).
• DFT calculations confirmed lower ΔG for Ni₁V₁-MNs, indicating enhanced OER activity.

Conclusions:

• The synergistic coupling effect between Ni and V in Ni₁V₁-MNs significantly enhances OER performance.
• The developed NiV-MNs represent a highly efficient and stable electrocatalyst for OER.
• This work provides a new strategy for designing advanced MOF-based electrocatalysts.