Preparation Of Doped TiO₂and Photocatalysis Properites Research

Semiconductor TiO2can degrade organic pollutants in environment efficiently, which is difficult to be degraded by biologic methods.Fe-Eu, Fe-B, Fe-B-Eu codoped TiO2nanoparticle and had been prepared by sol-gel method. Their characteristics were investigated by XRD, BET, Raman, XPS, UV-vis and photocatalytic degradation for methyl blue (MB).In the system of Fe-Eu codoped TiO2, the results showed that Fe3+c ould incorporate into the lattice of anatase through substituting the sites of Ti4+and induce impurity level, which can narrow the band gap of TiO2and enhance the visible light absorption, while Eu3+are likely to be found as dispersed metal oxides within the crystal matrix or on the surface of TiO2. which can conduce to the charge-transfer transition between Eu3+ion f electors and the TiO2conduction or valence band. The photocatalytic activity of resulting Fe-TiO2, Eu-TiO2and Fe-Eu-TiO2samples were evaluated by methylene blue degradation both under ultraviolet irradiation and visible light irradiation. It was found that Fe-Eu-TiO2nanomaterials exhibited the highest photocatalytic activity, which could be attributed to the synergistic effect of doped Fe and Eu.In the system of Fe-B codoped TiO2the results showed that B3+was likely to weave into the interstitial TiO2structure, forming the chemical environment like Ti-O-B. Doping boron could induce impurity level above the valence band, which can narrow the band gap of TiO2and enhance the visible light absorption, lowered the band gap. The experience of photocatalytic activity indicated that doped Fe and Eu have the synergistic effect only under visible light irradiation.In the system of Fe-B-Eu codoped TiO2the results showed doping of Fe. B and Eu atoms could suppress the crystal growth of TiO2and the effect of Eu doping was more pronounced than that of Fe and B doping. The lattice parameters (i.e., increase in the c-axis) indicated that the effect of Fe doping was more pronounced than that of B doping, while Eu doping have no effect on the lattice deformation. The experience of photocatalytic activity indicated that doped Fe, B and Eu have the synergistic effect under visible light irradiation, and only Fe, Eu dopant have the synergistic effect under ultraviolet irradiation.