Research On Collaborative Photocatalytic Degration Of Sewage Water In Electric Field By Fe³⁺-Eu³⁺-TiO₂/FG Composite

Nanocrystalline titanium dioxide has been widely applicated in many important fields such as membranes, electronic devices, porous substrates, converting solar energy and the water purificadtion. Although advanced oxidation process with TiO2photocatalysts have been shown to be an effective alternative in this regard, the vital snag of TiO2semiconductor is that it absorbs a small portion of solar spectrum in the UV region (band gap energy of TiO2is3.2eV). To utilize maximum solar energy, it is necessary to shift the absorption threshold towards visible region. The shifting of TiO2absorption into visible light region is strongly influenced by an electronic modification of the catalyst through deposition of metal particles, selective metal ion doping, and surface sensitization. Many metal ion dopants for the TiO2system have already been reported by different journal. The facts were noted that introducing two or more proper metals onto nanocrystalline TiO2particles will improve the photocatalytic synergistic effect of TiO2. Becase of having incompletely occupied4f and empty5d orbitals rare earth metals often serve as catalyst or promote catalysis. Rare earth metal and transition metal ions codoped the nanocrystalline TiO2may achieve the same effect as the TiO2with codeposited by noble and transition metal ions. To the best of our knowledge, there are not more studies carried out on TiO2semiconductor particles codoped with two kinds of metal ions for photo-oxidative degradation of toxic compounds. The present study is focused on the photodegradation of carbendazim by nanocrystalline TiO2codoped with Fe3+and Er3-(Fe3+-Er3--TiO2/FG) under UV and visible light.In this work, Fe3+and Eu3+doped titanium photocatalysts with different molar ratio of Fe3+and Eu3+were prepared by sol-gel-microwave method in anhydrous ethanol media. Fe3+-Eu3+-TiO2/FG nano-photocatalyst were prepared by Fe3+-Eu3+-TiO2nanoparticles supporting on fiber-glas through heating in N2at500℃. Among different molar of ratio of Fe3+and Eu3+, the same molar of Fe3+and Eu3+doped TiO2showed best photocatalytic activity under UV and visible light. The SEM, TEM analyses showed that the crystalline size of Fe3+-Eu3+-TiO2nanoparticles were in the range of20-50nm. XRD showed that all peaks of Fe3+-Eu3+-TiO2correspond to anatase crystalline structure. Fluorescence and Uv-Vis spectra results showed that Fe3+-Eu3--TiO2extended absorption spectra into the visible region over the range400-800nm. The photocatalytic activity of Fe3+-Eu3+-TiO2/FG nano-photocatalyst was measured under UV and visible light in the different action of electric field using carbendazim as a target harmful substance. In this paper, we discussed the reaction order and the ralationship of optium dosage, degradation time, electric-field strength and degradation rate. The reactant concentration during the degradation of carbendazim was monitored by HPLC analysis. The results showed that catalytic activity of TiO2was enhanced by dopted Fe3+-Eu3+. Meanwhile, the photocatalytic degradation rate constant kapp (0.04666min-’) of Fe3+-Eu3+-TiO2/FG is higher than Fe3+and Eu3+single doped TiO2The kinetics and mechanism of the reaction suggested that the Eu3+-、Fe3+and electric promoted the photocatalysis by capturing the photogenerated electrons and may induce the formation of HO.