Visible light mediated photocatalytic degradation of gaseous trichloroethylene and dimethyl sulfide on modified titanium dioxide
Visible light mediated photocatalytic degradation of gaseous trichloroethylene and dimethyl sulfide on modified titanium dioxide
复制标题
DOI：
10.1016/j.apcatb.2005.04.017
复制
发表时间：
2005-10
影响因子：
22.1
通讯作者：
K. Demeestere;J. Dewulf;T. Ohno;P. Salgado;H. Langenhove
中科院分区：
文献类型：
--
作者：
K. Demeestere;J. Dewulf;T. Ohno;P. Salgado;H. Langenhove
本文报道了四种改性TiO 2光催化剂在可见光照射下降解气态挥发性有机物的潜力。分别用CdS和曙红Y敏化TiO 2 Degussa P25制备了两种改性光催化剂。另外两种光催化剂是S掺杂的TiO 2。一种是通过最近描述的溶胶-凝胶法（S-掺杂的TiO 2-SG）制备的，而一种新的类型是通过物理混合法（S-掺杂的TiO 2-PM）合成的。所有改性的光催化剂都显示出紫外-可见吸收向更高波长（高达λ= 620 nm）的偏移。以三氯乙烯（TCE）和二甲基硫醚（DMS）为目标气体，在间歇式反应器中系统研究了近紫外和可见光照射下的光催化活性。虽然在近紫外光照射下，TiO_2 Degussa P25的TCE降解率比改性的光催化剂高1.3-6.6倍，但在λ> 400 nm处没有观察到显著的活性。相比之下，改性催化剂在蓝光（400- 540 nm）和黄光（480- 720 nm）照射下均表现出光催化活性，其中S掺杂的TiO 2-PM和S掺杂的TiO 2-SG分别给出最高的TCE降解率。在日光照射下（400- 720 nm），S掺杂的TiO 2-PM对TCE和DMS的降解产生最高的活性，例如在高达537 ppmv的浓度下照射110 min内的去除率高于99%。
This paper reports the potential of four modified TiO2photocatalysts to degrade gaseous volatile organic compounds under visible light irradiation. Two modified photocatalysts were prepared by sensitizing TiO2Degussa P25 with CdS and eosin Y, respectively. Two other photocatalysts were S-doped TiO2. One was prepared through a recently described sol–gel method (S-doped TiO2-SG), whereas a new type was synthesized by a physical mixture method (S-doped TiO2-PM). All modified photocatalysts showed a shift in UV–vis absorbance towards higher wavelengths, up to λ=620nm. Photocatalytic activity under near-UV and visible light irradiation was systematically investigated through the degradation of gaseous trichloroethylene (TCE) and dimethyl sulfide (DMS) in a batch reactor. Although TiO2Degussa P25 showed 1.3–6.6 times higher TCE degradation rates than modified photocatalysts under near-UV irradiation, no significant activity was observed at λ>400nm. In contrast, modified catalysts showed photocatalytic activity under both blue (400–540nm) and yellow light (480–720nm) irradiation, with S-doped TiO2-PM and S-doped TiO2-SG giving the highest TCE degradation rates, respectively. Under daylight irradiation (400–720nm), S-doped TiO2-PM yielded the highest activity towards both TCE and DMS degradation, exemplified by removal efficiencies higher than 99% within 110min of irradiation at concentrations up to 537ppmv.