作者机构：
[Zeng R.] College of Chemistry and Materials Science, Hengyang Normal University, Hengyang, 421008, China;Key Laboratory of Functional Organometallic Materials of Hengyang Normal University, College of Hunan Province, Hengyang, 421008, China;[戴友芝] College of Chemical Engineering, Xiangtan University, Xiangtan, 411105, China;[冯泳兰; 刘梦琴; 张复兴; 彭刚] College of Chemistry and Materials Science, Hengyang Normal University, Hengyang, 421008, China, Key Laboratory of Functional Organometallic Materials of Hengyang Normal University, College of Hunan Province, Hengyang, 421008, China;[唐文清] College of Chemistry and Materials Science, Hengyang Normal University, Hengyang, 421008, China, Key Laboratory of Functional Organometallic Materials of Hengyang Normal University, College of Hunan Province, Hengyang, 421008, China, College of Chemical Engineering, Xiangtan University, Xiangtan, 411105, China
通讯机构：
[Zeng, R.] C;College of Chemistry and Materials Science, Hengyang Normal University, Hengyang, China
关键词：
烟秸杆;生物炭;吸附;动力学;热力学
摘要：
以农业废弃物烟秸杆为原料,以KH_2PO_4为活化剂,制备了烟秸杆生物碳(简称TSC_(500)),通过静态吸附实验研究了TSC_(500)对含Cr(Ⅵ)废水的吸附性能。采用比表面积分析仪对TSC_(500)进行了测试,实验考察了pH值、吸附剂用量、吸附时间、Cr(Ⅵ)初始浓度和温度对Cr(Ⅵ)吸附的影响,深入研究了TSC_(500)对Cr(Ⅵ)的吸附行为。结果表明,在pH=3、温度313 K条件下,0.2 g TSC_(500)吸附100 mg/L Cr(Ⅵ),去除率和吸附容量分别达到91.32% 和45.66 mg/g,Langmuir和Freundlich比Temkin等温模型更好地拟合吸附实验数据;准一级和准二级动力学模型均能较好地描述该吸附行为,相关系数高达0.99;计算得到热力学参数ΔG~θ、ΔH~θ和ΔS~θ值表明该吸附过程为自发吸热过程。
作者机构：
[Li, Jun; Feng, Haibo; Li, Junhua; Jiang, Jianbo; Qian, Dong; Zhang, Yaqian] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Junhua; Feng, Yonglan] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Li, Junhua; Qian, Dong] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Qian, Dong] C;Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Gold nanoparticles;Reduced graphene oxide;Electrochemical sensing;Sudan I
摘要：
In this paper, we are presenting a facile, green and in situ synthesis strategy for the convenient preparation of well-dispersed gold nanoparticles (AuNPs)-decorated reduced graphene oxide (RGO) without the use of any template molecules and poisonous reductant. The as-synthesized nanocomposite has been detailedly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis as well as electrochemical technologies. The morphological and structural characterizations illustrate that AuNPs can be efficiently decorated on RGO with the Au content of 20.33 wt% in the matrix and the size of the embedded AuNPs vary between 25 and 40 nm. The electrochemical investigations confirm that the small-sized AuNPs on the RGO film can remarkably boost the electrocatalytic activity for the oxidation of Sudan I, which can be used as an enhanced electrochemical sensing platform for the sensitively detection of the toxicant Sudan I. Moreover, the kinetic parameter studies demonstrate that the Sudan I electro-oxidation at the AuNPs/RGO electrode is a diffusion-controlled process which involves two-electron and two-proton transfer. Under the optimal conditions, a wide linear range of Sudan I detection from 0.01 to 70 mu mol L-1 with good linearity (R-2 = 0.9965, 0.9942) and a low detection limit (1.0 nmol L-1, S/N = 3) were obtained. In comparison with the existing analogues ever reported, the AuNPs/RGO eletrode exhibits overwhelmingly superior comprehensive properties for the sensitive detection of Sudan I. Finally, the newly developed sensor was applied to quantitative determination of Sudan I in food samples such as chilli powder and ketchup sauce with satisfactory sensitivity, selectivity and reversibility.(C) 2015 Elsevier Ltd. All rights reserved.
摘要：
In this work, a fascinating hybrid based on Ag-Pd bimetallic nanoparticles-decorated graphene oxide (Ag-Pd/GO) has been successfully synthesized by a green and in situ chemical reduction strategy. The resultant hybrid was particularly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet-visible spectroscopy and electrochemical techniques. The morphological results illustrate that Ag-Pd nanoparticles in microspheric appearances are highly dispersed and embedded on the GO layers, resulting in a rough surface and three-dimensional (3D) microstructure with a high Ag-Pd content in the matrix. The as-synthesized 3D Ag-Pd/GO hybrid displays distinctly enhanced electrocatalytic activity for the vanillin oxidation in comparison with that of the monometal-decorated GO, revealing a synergistic effect of the matrix GO and the doped bimetallic Ag-Pd. Therefore, the Ag-Pd/GO composite can be used as an enhanced electrochemical sensing platform for the sensitive determination of vanillin, and the fabricated sensor displays a wide detection range of 0.02-45 mu mol dm(-3), low detection limit of 5 nmol dm(-3) and satisfactory recoveries between 98.8 % and 103.5 %. All the results demonstrate that the 3D hybrids integrated graphene with bimetallic nanoparticles are promising candidates for the development of high-performance electrochemical sensors. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
为了解湘江(衡阳段)底泥重金属污染程度,对流域内10个断面18个采样点的表层底泥重金属(Cu、Zn、As、Hg、Cd、Cr、Pb)进行采样,测定样品各金属含量,并分别采用潜在生态危害指数法和地累积指数法评价底泥重金属潜在生态风险和污染程度.结果表明,湘江(衡阳段)表层底泥中各点重金属平均 RI 为1009．46,总体上属于很强生态风险；地累积指数表明在松柏段面的砷、汞、镉、铅处于严重污染.
