The microporous tin dioxide nanoparticles (SnO₂ NPs) were synthesized by sol–gel method using isopropyl alcohol exhibit high surface area (128 m²/g). The crystal phase and geometry of SnO₂ NPs was studied by X-ray diffractometer and the calculated crystallite size is 15.78 nm. The percentage composition and purity was confirmed by energy dispersive X-ray analysis. The morphology was examined through scanning electron microscopy which confirm the presence of the grains, cluster and agglomerated particles in the sample. The space groups were assigned to different vibrational modes of the SnO₂ NPs on the basis of Raman spectroscopy. The surface functional moieties were identified by Fourier transform infrared spectroscopy. The batch method was used for the sorption of cadmium (Cd²⁺) ions from aqueous solution at pH 5. The Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) models were applied to the adsorption data to determine the nature adsorption process, binding energy and maximum sorption capacity of the adsorbent. A set of equations were used to study the thermodynamic feasibility and endothermic nature of the adsorption process while the ions exchange mechanism was found to be 1:1.

中文翻译：

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镉离子在异丙醇介导的二氧化锡纳米粒子上的建模，热力学研究和吸附机理

通过溶胶-凝胶法使用异丙醇合成具有高表面积（128 m ² / g）的微孔二氧化锡纳米粒子（SnO ₂ NPs ）。用X射线衍射仪研究了SnO ₂ NPs的晶相和几何形状，计算出的微晶尺寸为15.78 nm。通过能量色散X射线分析确认了组成和纯度的百分比。通过扫描电子显微镜检查形态，证实样品中存在晶粒，团簇和团聚颗粒。将空间组分配给SnO _2的不同振动模式基于拉曼光谱的NP。通过傅立叶变换红外光谱法鉴定表面功能部分。批处理法用于在pH 5时从水溶液中吸附镉（Cd ²⁺）离子。将Langmuir，Freundlich，Temkin和Dubinin-Radushkevich（D-R）模型应用于吸附数据以确定自然吸附过程，结合能和吸附剂的最大吸附能力。使用一组方程式研究了吸附过程的热力学可行性和吸热特性，发现离子交换机理为1：1。