Photocatalytic Activity Of Ce³⁺-Bi³⁺ Doped TiO₂Loading On Shell Base In Degradate Oil Spill

Photocatalysis is clean, green and economical, it is quite appropriate to degradate oil spill, and TiO2is broadly used in photocatalysis study for its stable, avirulent and low cost. However, TiO2has a large forbidden bandwidth and it can only absorb UV, which is quite poor in nature light. So in this study, I dope some Ce3+and Bi3+in TiO2, in order to expand the using of visible light. The result of Ce+-Bi+doped TiO2loading on shell base in degradate oil spill is quite good, that78.92%spilling oil can be degradated after15hours.Steeping shell base in photocatalyst sol-gel, after calcining, the photocatalyst will be loaded on the shell base. First, dope Ce3+in TiO2and set control experiment to find out that the best Ce3+doping amount is co%=2.0%and the best calcining temperature is500℃. Then, co-doped Ce3+and Bi3+in TiO2, determining the best Bi3+doping amount is co%=4.0%and the best calcining temperature is500℃as well. Under the best condition, the degradation rate of oil spill is78.92%after15hours.Further more, using SEM, TG, XRD and UV-Vis to analyse the doped TiO2. It can be confirmed that the surface structure, crystal form and spectral response range have changed after doped Ce3+and Bi3+into the TiO2, which can explain the searching result reasonably. The doped Ce3+will get into the TiO2crystal and display some Ti ion, which makes the crystal form changed. To compensate the distortion force, some O atom will dismiss from the TiO2crystal. The oxygen vacancy can capture the photon-generated carrier, which restrain the compound of photoproduct hole and electron, increasing the photocatalytic efficiency. Besides, doping Ce3+can import impurity energy level among the valence and conduction band of TiO2. In this condition, excitation electron can transition into the impurity energy level from valence band, and the electron in impurity energy can transition into the conduction band. That means that the large forbidden bandwidth of TiO2will be decreased and the luminous energy is reduced as well. So that, Ce+doped TiO2can absorb visible light to initiate the oil spill degradation. By the way, Ce3+doped TiO2has better load ability on the surface of shell base. It can be found from the SEM result that Ce3+doped TiO2is tight and uniform distributing on the shell base, and the particle size of TiO2is much smaller, that makes photocatalyst contact better with oil spill, which is benefit of photocatalysis. For doping Bi3+, it modify TiO2just similar with Ce3+However, co-doped Ce3+and Bi3+with TiO2is more efficient in oil spill degradation. According to the UV-Vis result, Ce3+and Bi3+co-doped TiO2has a larger spectral absorption range, and the oil spill degradation rate is higher than Ce3+doped TiO2as well.