Structure and Photocatalytic Properties of Mn-Doped TiO2 Loaded on Wood-Based Activated Carbon Fiber Composites

Mn-doped TiO₂ loaded on wood-based activated carbon fiber (Mn/TiO₂-WACF) was prepared by sol-gel and impregnation method using MnSO₄·H₂O as manganese source. The structure of Mn/TiO₂-WACF was characterized by SEM, XRD, FTIR, N₂ adsorption and UV-Vis, and its photocatalytic activity for methylene blue degradation was investigated. Results show that Mn-doped TiO₂ were loaded on the surface of wood-based activated carbon fiber with high-development pore structures. The crystallite sizes of Mn-doped TiO₂ in composites were smaller than that of the undoped samples. With an increase of Mn doping content, Ti-O bending vibration intensity of Mn/TiO₂-WACF increased and then decreased. Moreover, Ti-O-Ti and Ti-O-Mn absorption peaks increased upon doping of Mn. Mn/TiO₂-WACF with low specific surface area, and pore volume was improved at 3.5-6.0 nm of mesopore distributions due to the Mn-doped TiO₂ load. In addition, the UV-Vis showed that Mn/TiO₂-WACF (photodegradation rate of 96%) has higher photocatalytic activity than the undoped samples for methylene blue degradation under visible light irradiation.