Tadesse Aschalew, RamaDevi Dharmasoth, Hagos Mabrahtu, Battu GangaRao, Basavaiah K
Department of Inorganic and Analytical Chemistry, Andhra University Visakhapatnam-530003 India
Department of Applied Chemistry, Adama Science and Technology University Adama-1888 Ethiopia.
RSC Adv. 2018 Feb 23;8(16):8528-8536. doi: 10.1039/c8ra00158h.
As a remedy for environmental pollution, a simple synthesis approach has been developed to prepare nitrogen doped carbon quantum dot/magnetite nanocomposites (FeO@NCQDs NCs) using non-toxic and cost effective lemon juice as precursor for removal of organic dye pollutant. FeO@NCQDs NCs were characterized by using UV-Vis spectroscopy, FTIR, XRD, FESEM, EDS, TEM, VSM and TGA/DTA. TEM results show spherical shaped FeO@NCQDs NCs with an average particle size of 5 nm. Batch adsorption studies were done to investigate the tendency of the nanocomposites to remove representative methyl blue (MB) dye from aqueous solution. The effects of MB dye concentration, dosage of FeO@NCQDs NC adsorbent, pH, contact time and temperature were optimized by varying one variable while all the other parameters were kept constant. The experiment showed rapid removal of MB dye within 20 minutes with an adsorption efficiency of over 90.84% under optimum conditions. The adsorption process fits the Freundlich isotherm model well with and values of 0.993 and 1.842, respectively, at 298 K indicating the feasibility of the adsorption process. The adsorption process is spontaneous and involves exothermic behaviour as confirmed by thermodynamic studies. From a kinetic study, it was found that the pseudo-second order model is more suitable to describe the adsorption process than the pseudo-first order model for adsorption of MB dye onto FeO@NCQDs NCs.
作为一种环境污染治理方法，人们开发了一种简单的合成方法，以无毒且成本低廉的柠檬汁为前驱体来制备氮掺杂碳量子点/磁铁矿纳米复合材料（FeO@NCQDs NCs），用于去除有机染料污染物。采用紫外可见光谱、傅里叶变换红外光谱、X射线衍射、场发射扫描电子显微镜、能谱分析、透射电子显微镜、振动样品磁强计和热重/差示热分析等手段对FeO@NCQDs NCs进行了表征。透射电子显微镜结果显示，FeO@NCQDs NCs呈球形，平均粒径为5纳米。进行了批量吸附研究，以考察该纳米复合材料从水溶液中去除代表性甲基蓝（MB）染料的倾向。通过改变一个变量同时保持所有其他参数不变，对MB染料浓度、FeO@NCQDs NC吸附剂用量、pH值、接触时间和温度的影响进行了优化。实验表明，在最佳条件下，20分钟内可快速去除MB染料，吸附效率超过90.84%。在298 K时，吸附过程很好地符合Freundlich等温线模型， 和 值分别为0.993和1.842，表明吸附过程具有可行性。热力学研究证实，吸附过程是自发的，且表现为放热行为。动力学研究发现，对于MB染料在FeO@NCQDs NCs上的吸附，准二级模型比准一级模型更适合描述吸附过程。
