Manzoor Qaisar, Farrukh Muhammad Akhyar, Qamar Muhammad Tariq, Sajid Arfaa
Department of Chemistry, Forman Christian College (A Chartered University) Ferozepur road, Lahore 54600, Pakistan.
Department of Basic and Applied Chemistry, Faculty of Science and Technology, University of Central Punjab, Lahore, Pakistan.
Int J Biol Macromol. 2025 Jun;311(Pt 3):144009. doi: 10.1016/j.ijbiomac.2025.144009. Epub 2025 May 6.
Graphene oxide/MnO/chitosan (GO/MnO/CS) nanocomposite showed distinct morphological changes and improved adsorption properties in wastewater treatment as compared to individual GO. GO was synthesized using modified Hummer's method and then functionalized with MnO nanoparticles and chitosan to prepare two nanocomposites: GO/MnO and GO/Mn/CS. Nanocomposites characterized by UV/Visible spectroscopy, XRD, FTIR, SEM, and TGA. The average crystallite sizes calculated from XRD analysis were 30 nm for GO/MnO and 31 nm for GO/MnO/CS. The nanocomposite showed a red shift in band gap from 3.85 eV (GO) to 2 eV (GO/MnO/CS), which led to enhanced adsorption capacity and photocatalytic activity. Adsorption experiments were conducted to assess the elimination of Cr (VI) ions by synthesized nanomaterials at various operational conditions. The maximum adsorption capacities (q) were 131.58, 150.64 and 179.28 mg/g for GO, GO/MnO, and GO/MnO/CS respectively, at pH 2. The adsorption behavior of Cr (VI) onto the synthesized nanocomposites followed the Freundlich isotherm model, indicating multilayer adsorption on a heterogeneous surface. Kinetic studies revealed that the process followed a pseudo-second-order model, suggesting chemisorption as the dominant mechanism.
与单独的氧化石墨烯（GO）相比，氧化石墨烯/二氧化锰/壳聚糖（GO/MnO/CS）纳米复合材料在废水处理中表现出明显的形态变化和改善的吸附性能。采用改进的Hummer法合成GO，然后用二氧化锰纳米颗粒和壳聚糖进行功能化，制备了两种纳米复合材料：GO/MnO和GO/Mn/CS。通过紫外/可见光谱、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和热重分析（TGA）对纳米复合材料进行表征。根据XRD分析计算出的平均微晶尺寸，GO/MnO为30纳米，GO/MnO/CS为31纳米。该纳米复合材料的带隙从3.85电子伏特（GO）红移至2电子伏特（GO/MnO/CS），这导致吸附容量和光催化活性增强。进行吸附实验以评估合成的纳米材料在各种操作条件下对六价铬（Cr(VI)）离子的去除情况。在pH值为2时，GO、GO/MnO和GO/MnO/CS对Cr(VI)的最大吸附容量（q）分别为131.58、150.64和179.28毫克/克。Cr(VI)在合成的纳米复合材料上的吸附行为遵循Freundlich等温线模型，表明在异质表面上的多层吸附。动力学研究表明，该过程遵循准二级模型，表明化学吸附是主要机制。
