Sitko Rafal, Janik Paulina, Feist Barbara, Talik Ewa, Gagor Anna
Institute of Chemistry and ‡Institute of Physics, University of Silesia , Katowice, Poland.
ACS Appl Mater Interfaces. 2014 Nov 26;6(22):20144-53. doi: 10.1021/am505740d. Epub 2014 Oct 31.
The aminosilanized graphene oxide (GO-NH2) was prepared for selective adsorption of Pb(II) ions. Graphene oxide (GO) and GO-NH2 prepared through the amino-silanization of GO with 3-aminopropyltriethoxysilane were characterized by scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The batch experiments show that GO-NH2 is characterized by high selectivity toward Pb(II) ions. Adsorption isotherms suggest that sorption of Pb(II) on GO-NH2 nanosheets is monolayer coverage, and adsorption is controlled by a chemical process involving the surface complexation of Pb(II) ions with the nitrogen-containing groups on the surface of GO-NH2. Pb(II) ions can be quantitatively adsorbed at pH 6 with maximum adsorption capacity of 96 mg g(-1). The GO-NH2 was used for selective and sensitive determination of Pb(II) ions by electrothermal atomic absorption spectrometry (ET-AAS). The preconcentration of Pb(II) ions is based on dispersive micro solid-phase extraction in which the suspended GO-NH2 is rapidly injected into analyzed water sample. Such features of GO-NH2 nanosheets as wrinkled structure, softness, flexibility, and excellent dispersibility in water allow achieving very good contact with analyzed solution, and adsorption of Pb(II) ions is very fast. The experiment shows that after separation of the solid phase, the suspension of GO-NH2 with adsorbed Pb(II) ions can be directly injected into the graphite tube and analyzed by ET-AAS. The GO-NH2 is characterized by high selectivity toward Pb(II) ions and can be successfully used for analysis of various water samples with excellent enrichment factors of 100 and detection limits of 9.4 ng L(-1).
制备了氨基硅烷化氧化石墨烯（GO-NH₂）用于选择性吸附Pb(II)离子。通过氧化石墨烯（GO）与3-氨丙基三乙氧基硅烷进行氨基硅烷化反应制备的GO和GO-NH₂，采用扫描电子显微镜、粉末X射线衍射、X射线光电子能谱和拉曼光谱进行了表征。批量实验表明，GO-NH₂对Pb(II)离子具有高选择性。吸附等温线表明，Pb(II)在GO-NH₂纳米片上的吸附为单层覆盖，吸附过程受化学过程控制，涉及Pb(II)离子与GO-NH₂表面含氮基团的表面络合。Pb(II)离子在pH 6时可被定量吸附，最大吸附容量为96 mg g⁻¹。GO-NH₂用于通过电热原子吸收光谱法（ET-AAS）选择性和灵敏地测定Pb(II)离子。Pb(II)离子的预富集基于分散微固相萃取，即将悬浮的GO-NH₂快速注入分析水样中。GO-NH₂纳米片的褶皱结构、柔软性、柔韧性以及在水中的优异分散性等特性，使其能够与分析溶液实现良好接触，并且对Pb(II)离子的吸附非常迅速。实验表明，在分离固相后，吸附了Pb(II)离子的GO-NH₂悬浮液可直接注入石墨管并通过ET-AAS进行分析。GO-NH₂对Pb(II)离子具有高选择性，可成功用于分析各种水样，具有100的优异富集因子和9.4 ng L⁻¹的检测限。
