Photocatalytic degradation of pollutants offers an effective strategy for mitigating environmental contamination. This study reports the synthesis of porous TiO₂ aerogel nanocomposites, co-doped with Pt and Mn, via a one-pot sol-gel process followed by supercritical drying. These materials were evaluated for the degradation of methyl paraben (MeP) under UV-A irradiation.
The design of this photocatalyst combines bimetallic modification with a highly porous framework, creating synergistic surface and interface interactions. X-ray diffraction analysis confirmed the preservation of a pure anatase phase upon co-doping. Morphological and textural characterizations revealed spherical nanoparticles assembled into a highly porous network with a large specific surface area.
XPS and elemental mapping demonstrated the homogeneous dispersion of Pt and Mn species on the TiO₂ surface. Optical properties showed a red shift in the absorption edge along with band gap narrowing, reflecting modifications in the electronic structure induced by co-doping. Photoluminescence analysis revealed a pronounced decrease in emission intensity for the co-doped samples, indicating suppressed electron-hole recombination due to the combined charge trapping effect of Pt and Mn.
Photocatalytic experiments demonstrated significantly enhanced activity of the Pt-Mn/TiO₂ nanocomposites compared to pristine TiO₂, following pseudo-first-order kinetics. The 0.6%Pt-0.6%Mn/TiO₂ sample exhibited the highest performance, achieving 93% MeP degradation within 120 minutes under UV-A irradiation, along with good stability over four cycles.
These results demonstrate that the enhanced photocatalytic activity is driven by synergistic surface modification induced by Pt and Mn, which effectively promotes charge separation. This work emphasizes the pivotal role of dopant-induced surface and interface engineering in governing photocatalytic performance for water treatment applications.
