In-Situ Anchoring Pb-Free Cs3Bi2Br9@BiOBr Quantum Dots on NHx-Rich Silica with Enhanced Blue Emission and Satisfactory Stability for Photocatalytic Toluene Oxidation

All-inorganic metal halide perovskite quantum dots (QDs) have attracted attention from researchers with their fascinating optoelectronic properties. However, blue-emitting perovskite QDs typically have low photoluminescence quantum yield (PLQY). For potential commercial applications, it is preferable to replace Pb with an element having low toxicity. Here, Pb-free Cs3Bi2Br9@BiOBr perovskite QDs were anchored on the surface of NHx-rich monodisperse silica (A-SiO2) via N-Bi chemical bonding to isolate QDs from each other, thus enhancing efficient surface passivation and suppressing optical decay. Compared to unanchored QDs, Cs3Bi2Br9@BiOBr QDs/A-SiO2 composites exhibited significantly enhanced blue emission performance, the PLQY of which increased from 16.62 % to 77.26 %, in addition to good water and environmental stability. Finally, the novel composites as photocatalysts were used to drive the oxidation of toluene, a template reaction of C(sp(3))-H bond activation and demonstrated astonishing conversion rates (4317 mu mol g(-1) h(-1)) with high selectivity (around 87 %).

Automated summary

In this study, anchored Pb-free Cs3Bi2Br9@BiOBr perovskite quantum dots/A-SiO2 composites were developed, showing improved blue emission performance and good stability. These composites were successfully employed as photocatalysts for the oxidation of toluene, demonstrating high conversion rates and selectivity.