Decoding Tio ₂ Nanoparticle Formation via Nanotube Disintegration: Synthesis, Thermal Transformation, and Photocatalytic Synergy

This work investigates the thermal and structural transformation of TiO 2 nanoparticles (TiO 2 NPs) generated through electrochemical anodization in a fluoride‐based electrolyte, with a focus on understanding their formation via nanotube fragmentation. This disintegration pathway, characteristic of a top‐down progression, is modeled and visualized to clarify the origin of the nanoparticles. Temperature‐controlled annealing (100–1000 °C) governs phase behavior, crystallinity, and surface properties, with Na 2 Ti 6 O 13 emergence linked to a suppressed anatase‐to‐rutile transformation. TiO 2 NPs annealed at 400 °C demonstrate peak photocatalytic activity, achieving 77% caffeine degradation. These insights bridge formation mechanism and functional performance, offering a pathway‐based perspective on material tailoring.