Facile green synthesis of a dahlia-like anatase/TiO2(B) phase junction for boosting the photocatalytic degradation of persistent tetracycline

Abstract

The simultaneous construction of a phase junction and hierarchical porous architecture can efficiently promote the separation and transfer of photogenerated carriers and then greatly improve the photocatalytic activity of nano-TiO₂, while its facile and green preparation is still urgently needed. Herein, a novel dahlia-like TiO₂ possessing both an anatase/TiO₂(B) phase junction and high specific surface area of 342.7 m² g⁻¹ was successfully fabricated by a facile and green deep eutectic solvent-tuning strategy. The higher specific surface area results from its 3D hierarchical structure assembled by 2D ultrathin nanosheets with mesopores. Owing to the its structural features, the synthesized TiO₂ showed a superior photocatalytic activity and favorable stability for persistent tetracycline degradation, compared with pure anatase TiO₂, pure TiO₂(B) and commercial P25. Based on the trapping experiments of active radical species, ESR spectra and experimental results, a reasonable photocatalytic mechanism of tetracycline degradation was proposed. These research results will provide an efficient strategy for the green preparation and practical application of multifunctional advanced catalysts.