Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo, 11795, Egypt.
Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo, 11795, Egypt.
Int J Biol Macromol. 2018 Mar;108:1185-1198. doi: 10.1016/j.ijbiomac.2017.11.028. Epub 2017 Nov 11.
This research aimed to synthesize natural polymer nanocomposite and employ it for coupled adsorption- photocatalytic degradation of crystal violet. Sodium alginate-g-poly (acrylic acid-co-cinnamic acid) and its composites with ZnO nanorods and graphene oxide sheets were synthesized and characterized using FT-IR, XRD, SEM, HR-TEM and DR/UV-vis spectroscopy. The adsorption efficiency of samples for crystal violet has been studied in the dark. The effect of different parameters as pH, initial dye concentration, contact time and temperature on the adsorption efficiency of the synthesized sample has been examined. Kinetics studies showed that the adsorption of all samples was well described by the pseudo-second-order model and the equilibrium adsorption results fitted Freundlich model. The maximum adsorption capacity achieved at pH 5.0 was 13.85 mg g. Thermodynamic studies exhibited that the adsorption is spontaneous, endothermic in nature and leads to higher entropy. Coupled adsorption-photocatalytic degradation studies under sunlight showed an enhancement in the removal efficiency by 10%. In the case of sodium alginate-g-poly (acrylic acid-co-cinnamic acid)/ZnO/graphene oxide composite, the removal efficiency after 5 h under sunlight was 94% versus 84% in the dark.
本研究旨在合成天然聚合物纳米复合材料，并将其用于结晶紫的偶联吸附-光催化降解。通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、扫描电子显微镜（SEM）、高分辨率透射电子显微镜（HR-TEM）和漫反射/紫外可见光谱（DR/UV-vis）对海藻酸钠-g-聚（丙烯酸-co-肉桂酸）及其与氧化锌纳米棒和氧化石墨烯片的复合材料进行了合成和表征。研究了样品对结晶紫的暗吸附效率。考察了不同参数（如 pH 值、初始染料浓度、接触时间和温度）对合成样品吸附效率的影响。动力学研究表明，所有样品的吸附均较好地符合准二级动力学模型，平衡吸附结果符合 Freundlich 模型。在 pH 值为 5.0 时，最大吸附容量达到 13.85mg/g。热力学研究表明，吸附是自发的、吸热的，导致熵增加。在阳光照射下进行的偶联吸附-光催化降解研究表明，去除效率提高了 10%。在海藻酸钠-g-聚（丙烯酸-co-肉桂酸）/氧化锌/氧化石墨烯复合材料的情况下，在阳光照射下 5 小时后的去除效率为 94%，而在黑暗中的去除效率为 84%。
