Interface-engineered CsPbBr3–TiO2 nanocomposites for efficient and selective photocatalytic conversion of HMF to DFF

Abstract

We report a stable and selective photocatalyst for solar-driven oxidation of 5-hydroxymethylfurfural (HMF) using in situ TiO₂ coated CsPbBr₃ quantum dots (QDs). Controlled TiO₂ encapsulation at 120 °C preserves the structural integrity of the QDs, enhances colloidal stability, and forms a type II heterojunction that facilitates charge separation. The optimized nanocomposite achieves high conversion to 2,5-diformylfuran (DFF) with 90% selectivity under visible light irradiation using TEMPO as a redox mediator. Optical and post-reaction analyses confirm improved stability and suppressed Pb leaching. This work demonstrates that nanoscale interface engineering, combined with mild oxidative pathways, can enable the efficient and selective valorization of biomass-derived substrates.