用吸附相反应技术制备弱光响应的铈掺杂TiO2复合光催化剂

为拓展多相光催化的实际应用和满足环境治理的严格要求，利用吸附相反应技术设计并制备了弱紫外光响应高效的TiO2 多组分催化剂。借助透射电子显微镜、高分辨率透射电子显微镜和X 射线衍射分析了不同焙烧温度下铈离子掺杂量对催化剂形貌的影响，并结合光致发光光谱和弱光降解甲基橙过程，探索了催化剂结构变化对光生载流子复合率和弱光催化活性的影响。结果表明，当掺杂量较低（小于0.10%）时，铈离子掺入引起TiO2 晶格膨胀，从而引入光生载流子的浅能级捕获中心，提升了催化活性；在较高掺杂量（0.20% 以上）时， 铈离子掺入抑制了TiO2 结晶，催化剂中大量无定形TiO2 严重抑制了其活性；焙烧温度越高，铈离子掺杂量对催化剂结构和活性的影响越显著；降解高浓度甲基橙时，催化性能最好的催化剂的活性是商用P 25 的2 倍多。

Preparation of weak-light-driven TiO2 composite photocatalysts by adsorption phase synthesis

In order to expand the practical application of photocatalysis and meet the increasingly stringent environmental requirements, weak UV light-driven TiO2composite photocatalysts with high performance werepreparedby adsorption phase synthesis. Transmission electron microscopy, high resolution transmission electron imcroscopy and X-raydiffraction were employed to characterize the morphology of differentcatalysts. Combining the results byphotoluminescencespectra with the degradation of methyl-orange excited by weak UV light, the influence of the catalyst structure on the recombination of photogenerated carriers and its photocatalytic activity was expolred. The results indicate that Ce3+ doping with low doping content (less than 0.10%) leads to the lattice expansion of TiO2 and introduced some shallow capture sites for photogenerated carriers, thus enhancing the activity of the catalyst. At high doping content (≥ 0.20%), Ce3+ doping greatly inhibites the crystallization of TiO2 and caused a large amount of amorphous TiO2 in the catalysts, which significantly depressed the photocatalytic activity illuminated under weak UV light. The higher the calcination temperature is, the more obvious the effect of Ce3+ doping on the structure and activity of the catalysts is.For photodegradation for methyl-orange with high concentration, the degradation efficiency of the optimum catalyst is two timeshigher than that ofthe commercial photocatalyst P25.