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

Abstract

3D monolithic integrated photocatlysts were prepared by selfassembly of graphene platelets decorated with manganese doped TiO 2 nanoparticles. The self-assembly was induced by chemical reduction at mild reaction conditions. The physicochemical 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 TiO 2 to 2.8 eV in the monolithic composite made of rGO and TiO 2 . 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.

A green synthesis of nanocatalysts based on reduced graphene oxide/magnetic nanoparticles for the degradation of Acid Red 1

“…They were already incompatible with the water solvent and spontaneously selfassembled into 3D porous nanostructures. 40,41 When this process was performed in the presence of the FeSO 4 $7H 2 O precursor for the Fe 3 O 4 NPs, as a result of the simultaneous reduction of GO and the precursor, hydrophobic rGO nanoplatelets decorated with Fe 3 O 4 NPs were assembled into a 3D composite nanostructure. Subsequently, the as-obtained 3D structures were swollen in water and then dried using the freeze-drying technique, resulting the formation of ultralow density aerogels.…”

Hybrid Organic–Inorganic Membranes for Photocatalytic Water Remediation

“…Recent studies combine TiO 2 molecule with another compounds in order to improve the degradation of pollutants. For example, Nikola Toshikj et al [50] prepared by self-assembly method graphene platelets with manganese doped TiO 2 nanoparticles. In this study, they used the mentioned system in order to determine the degradation of MB in water after visible light irradiation.…”

High Performance COD Detection of Organic Compounds Pollutants using Sulfurized-TiO2/Ti Nanotubes Arrays Photoelectrocatalyst

“…In addition, its photosensitivity can be modi ed by doping so that its photosensitivity can be shifted from its original UV region to the visible region (11)(12)(13). Potential dopants that show high e ciency in improving the photoelectrical sensitivity of TiO 2 can be from the groups of metal or non-metal, such as iron (Fe) (14,15), cobalt Co (16), Nickel (Ni) (17,18), Copper (Cu) (19,20), silver (Ag) and Manganese (Mn) (21,22) from metals group and nitrogen (N) (23), sulphur (S) (24), phosphorus (P) (25) and uorine (F) (26) from the non-metals group. Non-metals dopant, particularly from the chalcogen, has shown a remarkable effect in enhancing the visible photoactivity of TiO 2 (27).…”