氧化石墨烯(GO)对罗丹明B染料的吸附行为研究
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摘要
本研究测试了氧化石墨烯(Graphene Oxide,GO)对罗丹明B染料的吸附效果,分析了不同pH、不同温度、不同离子强度对吸附效果的影响,并通过吸附等温模型和吸附动力学模型分析了GO对罗丹明B的吸附作用机理。结果表明,在pH=3、T=308K、离子浓度为0时GO对罗丹明B的吸附效果最佳,其最大吸附量为238 mg/g(初始浓度为60mg/L)。吸附等温模型拟合结果表明,GO对罗丹明B的吸附符合单分子层吸附过程,吸附动力学拟合结果表明GO对罗丹明B的吸附过程符合二级动力学模型。通过对GO进行循环吸附实验表明,经过多次吸附脱附试验后,GO对罗丹明B的再生吸附量仍可到95%以上。综合上述结果得知,GO对罗丹明B的吸附属于物理吸附,在改变环境条件时,吸附在GO表面的罗丹明B可快速从GO内孔隙脱离,将GO的活性位点释放,可实现GO的多次循环利用。基于GO具有较大的比表面积和丰富的活性位点,且GO的制备已实现商业化生产,GO在环境污染治理中将呈现巨大的发展前景。
In this study, the adsorption capacity of graphene oxides(GO) towards Rhodamine B(RhB) was studied with the influence of pH, degree and ionic strength. The results indicated in the condition of pH=3, electrical conductivity(EC)=0, T=308 K, GO showed the highest adsorption capacity(238 mg/g at the initial concentration of 60 mg/L) towards RhB. The isotherm obtained from experimental data fitted the Langmuir model. The kinetic study indicated that the adsorption of RhB onto GO followed the pseudo second-order model well. After three cycles' adsorption regeneration, the adsorption of GO reduced less than 5%. The results indicated the adsorption behavior of RhB on GO belonged to physical interaction. The high adsorption capacity and regeneration recycling rate indicate GO is an ideal adsorption materials towards cationic dyes like RhB.
In this study, the adsorption capacity of graphene oxides(GO) towards Rhodamine B(RhB) was studied with the influence of pH, degree and ionic strength. The results indicated in the condition of pH=3, electrical conductivity(EC)=0, T=308 K, GO showed the highest adsorption capacity(238 mg/g at the initial concentration of 60 mg/L) towards RhB. The isotherm obtained from experimental data fitted the Langmuir model. The kinetic study indicated that the adsorption of RhB onto GO followed the pseudo second-order model well. After three cycles' adsorption regeneration, the adsorption of GO reduced less than 5%. The results indicated the adsorption behavior of RhB on GO belonged to physical interaction. The high adsorption capacity and regeneration recycling rate indicate GO is an ideal adsorption materials towards cationic dyes like RhB.
引文
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[2]禹宝伟,申太力,王婷婷,等.三维磁性石墨烯泡沫的制备及其对亚甲基蓝的吸附研究[J].环境污染与防治,2017,39(7):730-734.
[3]姜遥,李青,徐朋飞,等.天冬氨酸-β-环糊精强化TiO2-石墨烯光催化降解酸性红的研究[J].环境污染与防治,2018,40(5):497-504.
[4]Tiwari J N,Mahesh K,Le N H,et al.Reduced graphene oxide-based hydrogels for the efficient capture of dye pollutants from aqueous solutions.Carbon,2013,56:173-182.
[5]Liu X,Gong W,Luo J,et al.Selective adsorption of cationic dyes from aqueous solution by polyoxometalate-based metal-organic framework composite.Applied Surface Science,2016,362:517-524.
[6]Wei M P,Chai H,Cao Y L,et al.Sulfonatedgraphene oxide as an adsorbent for removal of Pb(2+)and methylene blue.J Colloid Interface Sci,2018,524:297-305.
[7]Guo H,Jiao T,Zhang Q,et al.Preparation of Graphene Oxide-Based Hydrogels as Efficient Dye Adsorbents for Wastewater Treatment.Nanoscale Res Lett,2015,10(1):931.
[8]Liang J,Jiao Y,Jaroniec M,et al.Sulfur and nitrogen dual-doped mesoporousgrapheneelectrocatalyst for oxygen reduction with synergistically enhanced performance.AngewChemInt Ed Engl,2012,51(46):11496-500.