Ligand-Free Core–Shell Interface of CsPbBr ₃ /TiO ₂ Nanofibers for Modulating Electron Transfer

All-inorganic metal halide (IMH) perovskite and semiconductor core–shell nanomaterials have attracted attention as optoelectronic materials due to their potential to improve both the lifetimes and device functionality. However, the ligands used to synthesize IMH nanostructures stabilize the IMH but also introduce an insulating layer at the interface, which may hinder carrier transport. Herein, we report a ligand-free in situ synthesis of CsPbBr3/TiO2 core–shell nanofibers using hollow TiO2 nanofibers (HTNFs) fabricated via electrospinning as templates. The resulting one-dimensional (1D) heterostructures exhibit a uniform morphology, with CsPbBr3 confined within the hollow core and encapsulated by a protective TiO2 shell. This architecture enhances the photostability of the perovskite and facilitates efficient carrier transfer from the CsPbBr3 core to the TiO2 shell, resulting in a 1.8-fold increase in photocatalytic activity for the degradation of 2-mercaptobenzothiazole as compared to pristine HTNFs. Our approach offers a strategy for fabricating stable perovskite-based heterostructures without the need for organic surface ligands, making it highly attractive for next-generation photonic and photocatalytic devices.