改性绿色合成纳米氧化铁的特征及其对水溶液中Cd(2＋)的吸附

Modification and Characterization of Green Synthesized Iron Oxide Nanoparticles Used for Adsorption of Cd^(2+) in Aqueous Solution

以红背桂、桉树和樟树3种植物叶片的提取液制备绿色合成纳米氧化铁颗粒(Iron Oxide Nanoparticles,IONP),并比较了不同纳米氧化铁对水溶液中Cd^(2+)的吸附性能.结果表明,以红背桂提取液制备的纳米氧化铁(E-IONP)对Cd^(2+)的吸附效果最好.因此,通过对E-IONP在200~700℃下进行焙烧改性,研究了不同焙烧温度对E-IONP吸附能力的影响.研究发现,在300℃焙烧温度下改性的E-IONP(300℃-E-IONP)对Cd^(2+)的吸附效果较好,吸附量4.63 mg·g^(-1).XRD结果显示,未焙烧和200℃焙烧改性的E-IONP(EIONP、200℃-E-IONP)为无定型纳米氧化铁,300℃-E-IONP的主要成分为γ-Fe_2O_3和Fe_3O_4.此外,BET测试结果表明,E-IONP、200℃-E-IONP和300℃-E-IONP比表面积大小分别为5.645,86.167,62.219 m^2·g^(-1).300℃-E-IONP的磁滞回线呈"S"型,具有超顺磁性.研究结果表明,300℃-E-IONP是未来处理低浓度重金属废水最具潜力的吸附功能材料之一.

Iron oxide nanoparticles （IONP） were synthesized by extracts obtained from Excoe- carla cochinchinensis, Euealptus and Cinnamomum camphora leaves. The adsorption of Cd2 ＋ in a- queous solution using various IONP was compared, and the results show IONP from Excoecaria co- chinchinensis （E-IONP） that was best. Hence, E-IONP was thermally treated at the range of 200 700 ℃ to understand the absorption ability on Cd2＋. The highest adsorption capacity was observed at 300 ℃, with the adsorption quantity of 4. 63 mg ~ g-I XRD patterns showed that the E-IONP and E-IONP calcined at 200 ℃ were amorphous iron oxide, while were ＂,/-Fe203 and Fe304 at 300 ℃. In addition, the results from BET shows that the surface area of E-IONP and E-IONP calcined at 200 ℃, 300 ℃ was 5.645, 86. 167, 62. 219 m2 · g-l, respectively. ＂S＂ type was observed the hyster- esis loop of E-IONP calcined at 300 ℃ with superparamagnetism. The study shows that E-IONP is one of the most promising functional materials used for the future treatment of low-concentration heavy metal wastewater.