Coupling of nanocrystal hexagonal array and two-dimensional metastable substrate boosts H₂-production.

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Fabricating ordered nanocrystal arrays with subnanometer precision is challenging using traditional methods.
• Achieving controllable accuracy in nanoscale assembly is crucial for advanced material applications.

Purpose of the Study:

• To report a new platform for constructing well-ordered face-centered cubic rhodium nanocrystal arrays.
• To investigate the catalytic performance of these arrays for hydrogen evolution.

Main Methods:

• Utilized a two-dimensional layered metastable oxide, trigonal phase rhodium oxide, as a substrate.
• Constructed hexagonal arrays of rhodium nanocrystals with 0.5 nm intersurface distance.

Main Results:

• Demonstrated enhanced hydrogen spillover and acidic hydrogen evolution for H2 production.
• Achieved a low overpotential (9.8 mV at -10 mA cm-2) and Tafel slope (24.0 mV dec-1).
• Exhibited high stability under demanding conditions (-0.4 V vs. RHE at ~750 mA cm-2).

Conclusions:

• Metastable materials are key to designing advanced materials for high-performance catalysis.
• The developed rhodium nanocrystal arrays show significant potential for clean energy applications, particularly in hydrogen production.