Highly Aqueous Stability of Metal Oxides Encapsulated CsPbBr₃ Nanocrystals via A Generalized Core-Shell Engineering

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Metal halide perovskite nanocrystals (NCs) show great potential for optoelectronics.
• Perovskite NCs' sensitivity to water limits their use in aqueous photocatalysis.

Purpose of the Study:

• To enhance the aqueous stability and photocatalytic performance of perovskite NCs.
• To develop a generalizable core-shell engineering strategy for perovskite NCs.

Main Methods:

• An epoxide-mediated sol-gel process was used to deposit metal oxide shells (e.g., SnO2, Al2O3, Eu2O3) onto perovskite NCs.
• Characterization of the core-shell NCs' structure, optical properties, and stability in water.

Main Results:

• The core-shell perovskite NCs exhibited enhanced photoluminescence (PL) stability in water over 30 days.
• SnO2@CsPbBr3 NCs showed excellent water dispersibility (zeta potential ~42 mV).
• The engineered NCs achieved a high NH4+ production rate of 47 µmol g-1·h-1 for nitrogen fixation without sacrificial agents.

Conclusions:

• The core-shell strategy effectively improves the aqueous stability of perovskite NCs.
• This approach expands the application of perovskite NCs in aqueous environments, particularly for photocatalysis.
• The study provides a guideline for designing stable perovskite-based photocatalysts for nitrogen fixation.