Visible Light Photocatalysts Based on Manganese Doped TiO2 Integrated Within Monolithic Reduced Graphene Oxide/Polymer Porous Monolith

Abstract

Abstract3D monolithic integrated photocatlysts were prepared by self‐assembly of graphene platelets decorated with manganese doped TiO2 nanoparticles. The self‐assembly was induced by chemical reduction at mild reaction conditions. The physico‐chemical properties of the photocatalysts were improved by addition of polymer nanoparticles within the 3D structures. The rGO presence in the nanostructures affected their light absorption capability, which was red shifted. As a result, the band gap dropped from 3.12 eV in Mn doped TiO2 to 2.8 eV in the monolithic composite made of rGO and TiO2. The photocatalysts were applied for the elimination of methylene blue (MB) from aqueous solutions, the degradation of which was monitored by the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. It was shown that (i) MB was completely eliminated from aqueous solution; (ii) all the adsorbed MB was photocatalytically degraded under visible light, giving rise to various smaller molecules as intermediate products of degradation; and (iii) one part of the MB was completely mineralized, demonstrated by the presence of final degradation products. These results indicate that the presented materials seem to be a powerful tool in water purification process with double impact. On one hand, it will allow re‐use of water and decrease of its consumption in the textile producing plants, and on the other hand, it will assure protection of the environment by elimination of the hazards.