光谱法研究敏化的TiO_2纳米粒子光催化降解罗丹明B的途径

Study of Sensitized TiO_2 on Photocatalytic Degradation Paths of Rhodamine B by Spectroscopy Methods

采用sol-gel法制备了纳米氧化钛(TiO2),并用邻苯二甲酸(o-PTA)对TiO2进行敏化修饰,得到了邻苯二甲酸敏化纳米氧化钛(o-PTA/TiO2)催化剂.用傅里叶变化红外光谱(FT-IR)对其进行表征,发现邻苯二甲酸已经成功连接到TiO2的表面,并对其光催化性能进行了研究.以罗丹明B(RhB)为催化降解目标物,采用紫外/可见光谱(UV-V is)法和荧光光谱(FL)法对催化降解RhB的产物进行研究,结果显示,在可见光下TiO2催化降解RhB时,是直接矿化RhB;同条件下o-PTA/TiO2催化降解RhB时,是分步降解.对两种光催化路径的探究,可以为光催化降解以RhB为代表的一系列染料提供理论基础.研究表明,无论采用紫外/可见光谱法还是采用荧光光谱法对RhB的降解产物进行表征,都可以得到一致的结果,方法简便易操作.

The photocatalytic degradation products of Rhodamine B （RhB） on TiO2 nanopartical modified with Phtha- landione（ o-PTA）, which was prepared through the sol-gel mehtod, have been investigated by UV-vis spectroscopy and fluorescence spectroscopy. The results indicated that N-de-ethylation of RhB that leads to the generation of rhodamine- 110 was a prevailing path with o-PTA/TiO2, whereas the cleavage of the ehromophorie ring structure was dominant with pure TiO2. The two paths provided a theory base for the photocatalytic degradation of series of dye pollutants like RhB.