Decoding Tio2 Nanoparticle Formation via Nanotube Disintegration: Synthesis, Thermal Transformation, and Photocatalytic Synergy

Abstract

This work investigates the thermal and structural transformation of TiO2 nanoparticles (TiO2 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 degrees C) governs phase behavior, crystallinity, and surface properties, with Na2Ti6O13 emergence linked to a suppressed anatase-to-rutile transformation. TiO2 NPs annealed at 400 degrees 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.