Bromoacetyl Bromide-Derived CsPbBr₃ Quantum Dots: Robust Water Stability for Aqueous-Phase Photocatalysis

Area of Science:

• Materials Science
• Photocatalysis
• Quantum Dot Synthesis

Background:

• Cesium lead bromide (CsPbBr3) perovskites are efficient photocatalysts but limited to nonpolar solvents due to poor aqueous stability.
• Developing stable and recyclable photocatalysts for aqueous-phase reactions is crucial for sustainable chemistry.

Purpose of the Study:

• To develop a novel, one-step synthesis for highly water-stable cesium lead bromide quantum dots (QDs).
• To demonstrate the efficacy of these QDs as recyclable photocatalysts in aqueous media for organic transformations.

Main Methods:

• One-step synthesis of CsPbBr3 QDs using bromoacetyl bromide (BABr) and oleylamine (OAm).
• Characterization of QD properties and ligand structure using FTIR, NMR, XPS, and DFT studies.
• Evaluation of QD stability in aqueous media and photocatalytic activity in the azide-alkyne click reaction.

Main Results:

• Achieved high-quality, size-tunable CsPbBr3 QDs (emission 475-521 nm, PLQY 95-100%) with unprecedented aqueous stability (>2 months, 78% PL retention).
• The novel passivating ligand [2-bromo-N-(octadec-9-en-1-yl) acetamide] (BOAM) ensures QD stability and dispersibility in water (zeta potential +56 mV).
• Demonstrated the first use of CsPbBr3 QDs as recyclable photocatalysts for the click reaction in water, achieving ~100% yields at room temperature.

Conclusions:

• A facile synthesis method yields highly stable, water-dispersible CsPbBr3 QDs with tunable optical properties.
• The developed QDs represent a significant advancement for aqueous-phase photocatalysis, enabling sustainable organic transformations.
• This work opens new avenues for utilizing perovskite QDs in environmentally friendly catalytic processes.