聚乙二醇修饰ZIF-8的合成及对活性艳红的吸附

由于ZIF-8材料孔径较小,制约了其对大分子染料活性艳红的吸附,为了调节其孔径,结合有机膜制备中聚乙二醇(PEG)常作为孔调节剂,因此选择PEG作为软膜板剂对ZIF-8进行修饰复合,获得了一种新型的ZIF-8/PEG多孔纳米复合材料;采用XRD、SEM和氮气吸附-脱附等方法对ZIF-8/PEG进行表征。结果表明:合成了孔径有所增加的分级孔,形成了5~10 nm的介孔孔径,发现添加PEG改性后材料粒度变小,但比表面积不增反降,这是因为其介孔孔径的存在;考察了其对液相污染物偶氮废水——活性艳红X-3B的吸附性能,发现分子质量为2 ku的PEG改性其吸附量较未改性前提高26.7%,吸附量可达38.5 mg/g。

微波辅助制备巴旦木壳吸附剂对活性艳红X-B吸附性能研究

以新疆厚皮原味巴旦木去仁所得壳作为原料进行实验,通过0.7 mol/L氯化锌活化成活性炭。探索在不同频率的微波条件下,各种因素对巴旦木壳吸附活性艳红X-B的影响。微波协同巴旦木壳活性炭吸附剂对活性艳红X-B染料吸附有一定的效果,最佳吸附条件是0.5 g活性炭、100 mg/L活性艳红X-B染料、辐射时间2 min。吸附过程符合准二级动力学方程,是化学吸附。经过对比发现Langmuir吸附等温式拟合效果明显,是单分子层吸附。正交试验得出吸附量优化组合为t=1 min,m=0.6 g,c=300 mg/L;去除率组合:t=3 min,m=0.6 g,c=100 mg/L。极差分析得出吸附量优化组合为t=2 min,m=0.6 g,c=300 mg/L,影响顺序依次为染料浓度>吸附剂用量>吸附时间;去除率的优化组合:t=3 min,m=0.6 g,c=300 mg/L,影响顺序依次为染料浓度>吸附剂用量>吸附时间。方差分析得出,吸附量的影响顺序为染料浓度影响最大,吸附剂用量次之,吸附时间影响最小;去除率的影响顺序为染料浓度最大,吸附剂用量次之,吸附时间影响不大。

A simple and cheap method for preparation of coupled ZrO_(2)/ZnO with high photocatalytic activities

The objective of this study was to prepare a new photocatalyst with high activities for degradation of organic pollutants.Coupled ZrO_(2)/ZnO photocatalyst was prepared with a simple precipitation method with cheap raw materials zinc acetate and zirconium oxychloride,and was character-ized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).Reactive brilliant red X-3B was used as a model compound to investigate the photocatalytic activity of synthesized catalysts in water under 254 nm UV irradia-tion.Results show that the optimal calcination temperature and coupling molar ratio of Zr were 350°C and 2.5%,respec-tively.At the calcination temperature of 350°C,ZrO_(2) was dispersed on the surface of hexagonal ZnO in the form of amorphous clusters.The particle size of ZrO_(2)/ZnO decreased with the decrease of calcination temperature and the increase of Zr coupling amount.ZrO_(2)/ZnO has better photocatalytic activity for degradation of reactive brilliant red(RBR)X-3B than pure ZnO and P25-TiO_(2).