Photocatalytic degradation of TNT in wastewater using Fe-doped TiO_2 nanoparticles

摘要

Titanium(IV) oxide powders doped with nanocrystalline iron were synthesized by a sol-gel method. The function of iron is twofold: (i) it serves to improve the absorption of photons by TiO2 and (ii) it inhibits the recombination of electron-hole pairs in excited states. Iron content varies from 0 to 0.8 wt% of the powders being prepared. The surface morphology, phase transformation, surface characteristics and absorption bands of the nanopartides prepared for this exercise were examined. The physicochemical properties of the nanopartides prepared for the prepared catalysts were examined by special instrumental analytical methods: transmission electron microscopy for the surface morphology, X-ray diffraction for the phase transformation, Brurtauer-Emmett-Teller for surface characterization and UV-visible spectroscopy for determination of absorption bands. The phase transformation of TiO2 from anatase to ruffle was catalyzed by iron. It was observed that: (i) the grain size of TiO(2 )decreased with increasing iron content; (ii) the surface area of catalysts increased with increasing iron(III) oxide loading, up to 0.6 wt%; (iii) beyond 0.6 wt%, the surface area decreased with increasing iron content and (iv) the rate of photocatalytic degradation of trinitrotoluene was optimal at an iron content of 0.6 wt%.