论文部分内容阅读
采用溶胶凝胶法制备了不同原料比例碘铈共掺杂纳米TiO2催化剂,运用X射线光电子能谱(XPS),X射线衍射(XRD),透射电镜(TEM)等检测手段对催化剂进行了初步表征.结果表明,经过450℃煅烧处理得到的TiO2、铈掺杂TiO2以及碘铈共掺杂TiO2催化剂均为锐钛矿相,掺杂的Ce和I原子可能以I—Ce—O及O—Ti—I等键合方式进入TiO2晶格内部,此外,I-Ce离子共掺杂能有效降低TiO2表面的电子-空穴对的复合.以染料罗丹明B(Rhodamine B,RhB)和无色小分子水杨酸(Salicylic acid,SA)为降解的目标化合物,发现碘铈共掺杂的最佳物质的量之比为nCe∶nI∶nTi=0.04∶0.05∶1,即I0.05Ce0.04TiO2催化剂在可见光照射下(λ>420 nm)降解目标化合物其光化学活性明显优于单掺铈的TiO2催化剂和未掺杂的TiO2.该催化反应涉及到空穴氧化,并伴有羟基自由基(.OH)、超氧自由基(O2.-)及H2O2等氧化物种的产生.
The photocatalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) The results showed that TiO2 and cerium-doped TiO2 and iodine-cerium-codoped TiO2 obtained after calcination at 450 ℃ are anatase phase, and Ce and I atoms may be doped with I-Ce-O and O-Ti -I, etc. In addition, co-doping of I-Ce ions can effectively reduce the recombination of electron-hole pairs on the surface of TiO2. With Rhodamine B (RhB) and colorless Salicylic acid (SA) is the target compound for degradation, and the best ratio of the amount of iodine cerium co-doped is found to be nCe: nI: nTi = 0.04: 0.05: 1, that is, I0.05Ce0.04TiO2 catalyst Under visible light irradiation (λ> 420 nm), the photochemical activity of the target compound degraded significantly better than that of the single-doped cerium-doped TiO2 catalyst and undoped TiO2. The catalytic reaction involves hole oxidation accompanied by hydroxyl radicals ), Superoxide radical (O2.-) and H2O2 and other oxidative species.