摘要
利用水热合成法分别制备了Fe、Co、Ni掺杂及Fe—Co、Fe—Ni共掺杂的ZnO光催化剂。采用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、紫外一可见漫反射吸收光谱（UV—Vis）等手段对催化剂进行了表征。以氙灯（250—800nm）为光源，盐酸四环素为降解对象，模拟测试样品在日光下光催化降解抗生素的活性。考察了过渡金属种类、过渡金属掺杂量及二元掺杂配比对ZnO样品光催化活性的影响。结果表明，制得的样品均为六方晶系纤锌矿结构的ZnO。单一元素掺杂时，Fe掺杂提高了ZnO光催化活性，而Co、Ni掺杂都抑制了ZnO光催化活性。共掺杂时，Fe—Co／ZnO及Fe—Ni／ZnO光催化活性优于单一掺杂的Fe／ZnO，其中3％Fe-1％Ni／ZnO样品的光催化活性最好，在氙灯光源下反应120min对盐酸四环素的降解率高达87．95％。
The article is intended to introduce our work on preparing the Fe-doped, Co-doped, and other similar-doped photocatalysts via a hydrothermal synthesis method as well as the effect of transition metal doped on the ZnO Photocatalytic degradation of the tetracy- cline. Considering the above said research needs, we have character. ized the products concerned by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and ultraviolet and visible dif- fusion reflectance spectra （ UV - Vis DRS）. It is also from our re- search needs that we have evaluated the photocatalytic degradation activities of the antibiotics by using catalysts we have developed under the sunlight and under a xenon lamp （λ = 250 - 800 nm） irradiation. We have investigated the effects of the above mentioned transition metals, their concentrations, and the ratio of the two metals in co- doped ZnO samples on the photocatalytie efficiency. The results of our investigation and analysis have shown that the products prepared are all hexagonal wurtzite in structure of ZnO, whose crystallization tends to decrease with the increase of the transition metal ions doping concentration. We have also found that under the single transition metal ion doped, Co doping and Ni doping tend to defect the photo- catalytic activity of ZnO. However, the photocatalytic activity of Fe- doped ZnO photocatalyst samples can thus be greatly improved. To be exact, when the doping concentration is kept at 7%, the Fe/ZnO sample would like to exhibit the highest photocatalytic degradation rate. In addition, the UV - Vis results show that the absorbance spectra of ZnO tends to have a red shift with doping of Fe, whose range tends to extend with the increase of Fe doping concentration. Moreover, the photocatalytic performance of Fe- Co co-doped and Fe - Ni co-doped ZnO samples proves to be better than that of Fe doped ZnO, with the photocatalytic activity of 3 % Fe - 1% Ni/ZnO being highest. Furthermore, the photocatalytic degradation of tetracycline hydrochloride can be made as high as up to 87.95% in 120 rain un- der the irradiation of xenon lamp light. At this, we have also studied the samples from the kinetics of photocatalytic degradation of tetracy- cline hydrochloride. The result verifies that the photocatalytic degra- dation with doped and undoped ZnO in a slurry system tends to follow the first-order reaction mode, with the equation ln（p0/pt） = kt. The photodegradation reaction rate of 3 % Fe - 1 % Ni/ZnO sample turns to be highest, whose degradation constant k is 0.014 05 min-1.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期57-61,共5页
Journal of Safety and Environment
基金
高等学校博士学科点专项科研基金项目(20110205110014)
关键词
环境工程学
铁
钴
镍
共掺杂
氧化锌
光催化降解
四环素
environmental engineering
ferrum
cobalt
nickel
co- doped
zinc oxide
photocatalytic degradation
tetracycline
