In this work, magnetic cobalt nanoparticles (CoNPs) were synthesized and applied to the removal of Remazol golden yellow RNL (RGY) from aqueous solutions and textile wastewater. The CoNPs were characterized and the Co content found in the CoNPs was 60.38% (m/m). The analysis of X-ray Diffraction (XRD) and Raman Spectroscopy indicated the presence of Co⁰ and CoO in the composition of the material, as confirmed by Thermogravimetric Analysis coupled to Mass Spectrometry (TG-MS). Images obtained by the Transmission Electron Microscope (TEM) showed that the CoNPs have sizes smaller than 10 nm, sphere morphology and high agglomeration capacity. The results obtained by nitrogen adsorption-desorption suggested that the nanomaterial presented a mesoporous characteristic, low specific surface area (15.70 m² g⁻¹) and a pore volume and pore diameter of 0.072 cm³ g⁻¹ and 3.64 nm, respectively. CoNPs removed the RGY with high efficiency, reaching almost 100% removal in 30 min. The kinetic results showed that the reaction followed pseudo-second-order kinetics. Additionally, the removal process can be altered depending on the experimental condition. For instance, under acidic conditions, the reductive degradation prevailed, while in neutral or basic conditions, two simultaneous processes occur: reductive degradation and adsorption. Finally, CoNPs were applied to textile wastewater. The results showed high discoloration, reaching almost 88%. However, there was only a 32% decrease in chemical oxygen demand, showing that CoNPs are efficient at removing organic dyes from aqueous solutions.

在这项工作中，合成了磁性钴纳米粒子（CoNPs），并将其用于从水溶液和纺织废水中去除Remazol金黄色RNL（RGY）。表征了CoNP，并且CoNP中发现的Co含量为60.38％（m / m）。X射线衍射（XRD）和拉曼光谱分析表明，材料的成分中存在Co ⁰和CoO，这已通过热重分析与质谱（TG-MS）的结合得到证实。通过透射电子显微镜（TEM）获得的图像显示CoNP具有小于10nm的尺寸，球形形态和高聚集能力。通过氮吸附-解吸获得的结果表明，该纳米材料呈现出介孔特性，低的比表面积（15.70 m ² g ^-1）和孔体积和孔径为0.072 cm ³  g ^-1和3.64 nm。CoNPs高效去除了RGY，在30分钟内达到了几乎100％的去除率。动力学结果表明该反应遵循伪二级动力学。此外，可以根据实验条件更改去除过程。例如，在酸性条件下，主要发生还原性降解，而在中性或碱性条件下，同时发生两个过程：还原性降解和吸附。最后，将CoNPs应用于纺织废水。结果显示高度变色，达到几乎88％。但是，化学需氧量仅减少了32％，这表明CoNP可有效去除水溶液中的有机染料。