One-step template-free synthesis of Mn(II)-doped TiO2 hierarchical microspheres with unique radiating fibrous structure for efficient Fenton degradation

Herein, hierarchically spherical Mn(II)-doped TiO₂ with a radiating fibrous structure was synthesized for the first time via a simple one-step template-free solvothermal process. Such a unique structure endowed the material with a considerably large surface area (413.3 m² g⁻¹), which was the highest value ever reported for Mn(II)-doped TiO₂-type materials. Moreover, the large and straight inter-fiber pores (20–60 nm) were advantageous in facilitating fast molecular diffusion and promoting the accessibility of active sites. As a result, the hierarchical Mn(II)-doped TiO₂ was demonstrated to be a high-performance Fenton catalyst for degradation of organic pollutants in the presence of H₂O₂, with significantly higher catalytic efficiency than many previously reported heterogeneous Fenton catalysts. Moreover, the catalyst could maintain its original activity even after being reused several times. The simple synthesis, high catalytic activity, and excellent reusability indicate this hierarchical Mn(II)-doped TiO₂ is a promising candidate as a Fenton catalyst for wastewater treatment.