低温液相法制备掺铁氧化锌及其光催化活性

Preparation and Photocatalytic Activity of Fe-doped ZnO by Low-temperature Solution Method

探索低温液相法合成掺Fe的Fe∶ZnO,Fe∶Zn摩尔比为0.01~0.03,通过调整氢氧化钠的量来控制氧化锌的微观形貌,利用X射线衍射（XRD）、扫描电子显微镜（SEM）、X射线能谱仪（EDS）、紫外-可见光谱（UV-vis）、荧光光谱（PL）对所合成的材料进行表征,采用紫外照射测试样品对甲基橙的光催化降解率。结果表明：在80℃水溶液环境下低温合成及随后干燥,成功制备出了掺杂不同Fe含量的Fe∶ZnO纳米片,所获得的样品均为纤锌矿结构,结晶度高。随着Fe掺杂量的增加,样品的紫外-可见吸收光谱红移,在可见光区吸收增大,带隙减小;适量的Fe掺杂可以降低样品光生电子与空穴的复合率,提高样品光催化性能。掺杂Fe量为1.5%的Fe∶ZnO的样品光催化降解甲基橙的效率最高,紫外光照反应5h后对甲基橙的光催化降解率相对于纯的ZnO提高了43.8%。

Preparation and photocatalytic activity of Fe-doped ZnO with Fe/Zn molar ratio of 0.01-0.03 by low-temperature solution method were investigated. The micro-morphology of the Fe-doped ZnO samples was adjusted through the addition of NaOH solution. Using X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, X-ray energy spectrometer （EDS）, ultraviolet and visible （UV-vis） spectrophotometer, and photoluminescence （PL） spectroscopy, the structure, morphology and optical properties of Fe doped ZnO samples were characterized. And their photocatalytic activity towards degradation of methyl orange （MO） under ultraviolet irradiation were tested. The results show that Fe-doped ZnO nano- sheets with different contents of Fe can be successfully synthesized at 80℃ in aqueous solution and then well crystallized with hexagonal wurtzite structure after drying. With the increase of Fe doping in the samples, a red shift in UV-vis spectra can be detected and the band gap is narrower than the theoretical value. Furthermore, an appropriate Fe concentration of Fe-doped ZnO decreases the recombination rate of free charge carriers, thus enhances their photocatalytic activity. The Fe＂ ZnO sample with 1.5 at% Fe exhibits the best photocatalytic activity towards degradation of MO, and its degradation rate is improved by 43.8% over pure ZnO when irradiated under UV lamp during 5 hours.