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以活性炭为载体,通过溶胶-凝胶法分别制备了Fe、Ag、Zn、Mn和Cr过渡金属离子掺杂TiO2/活性炭(X-TiO2/AC,X-TA;X:过渡金属离子)复合体,利用X射线衍射(XRD)、比表面积(BET)、X光电子能谱(XPS)、扫描电镜(SEM)、电子自旋共振谱(ESR)和荧光光谱(FS)对其结构进行表征.以罗丹明B的光催化降解为探针实验,评价掺杂负载型复合体的双协同光催化性能和使用寿命,提出双协同光催化扩增机制,并探讨了掺杂率和负载率对双协同扩增效果影响.结果表明:通过活性炭吸附和离子掺杂对TiO2光催化性能表现出双协同扩增作用,导致X-TA对罗丹明B的降解速率常数kapp大于掺杂X-TiO2粉体和TA负载体之和.同时,掺杂率和负载率共同影响协同效应,当Fe离子掺杂率和Fe-TiO2负载率分别为0.3%和10%时,Fe-TA复合体kapp最大为0.0208min-1.另外,过渡金属离子掺杂对TiO2光催化性能提高程度按掺杂离子Ag、Zn、Mn、Cr、Fe递增.掺杂后金属离子的价态、得电子能力、比表面积和掺杂TiO2颗粒尺寸上的差异决定了不同离子掺杂负载型复合体催化性能不同,复合体寿命降低的主要原因是由于活性组分从载体上流失所引起.
The activated carbon was used as the carrier to prepare the composite of TiO2 / activated carbon (X-TiO2 / AC, X-TA; X: transition metal ions) doped with transition metal ions of Fe, Ag, Zn, Mn and Cr respectively by sol- , The structure of which was characterized by XRD, BET, XPS, SEM, ESR and FS. The structures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron spin resonance spectrum Rhodamine B photocatalytic degradation as a probe experiment to evaluate the doubly coordinated photocatalytic performance and service life of the doped composite, proposed a double synergistic photocatalytic amplification mechanism, and discussed the doping rate and loading rate on the double synergistic effect The results showed that the photocatalytic activity of TiO2 by X-TA showed a double synergistic effect through the adsorption of activated carbon and ionic doping, which led to the fact that the degradation rate constant kapp of X-TA to rhodamine B was larger than that of X-TiO2 powder and TA carrier, and the doping rate and loading ratio all affect the synergistic effect. When the Fe doping rate and the Fe-TiO2 loading rate are 0.3% and 10% respectively, the maximum kappa ratio of Fe-TA composite is 0.0208min -1. In addition, the transition metal ions doping TiO2 photocatalytic performance improvement according to the doping ions Ag, Zn, Mn, Cr, Fe The difference between valence state, electron ability, specific surface area and doping TiO2 particle size of doping metal ions determines the catalytic performance of different doping doped composite, the main reason for the decrease of the life of the composite is due to the activity The loss of components from the carrier caused.