Methyl orange (MO) and methylene blue (MB) dyes are toxic and carcinogenic; thus, their presence in water bodies has been a major concern. Designing an efficient adsorbent for removal of these dyes is a scientific challenge for researchers. In this work, a polypyrrole–tannic acid nanocomposite was prepared via a chemical oxidation method and used as a novel adsorbent for removing these toxic dyes. The synthesized nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller methods. The effect of different parameters on adsorption such as adsorbent doses, temperature, pH, initial dye concentration, and contact time was studied. The adsorption was in line with pseudo-second-order kinetics and the Langmuir isotherm model. ΔG°, ΔH°, and ΔS° were calculated to ascertain the feasibility of adsorption. The maximum adsorption capacities attained for this adsorbent were found to be 204.08 mg/g toward the MO dye and 217.39 mg/g toward the MB dye.

中文翻译：

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提高有机染料对聚吡咯/单宁酸纳米复合材料的吸附


甲基橙 （MO） 和亚甲基蓝 （MB） 染料有毒且致癌;因此，它们在水体中的存在一直是一个主要问题。设计一种用于去除这些染料的高效吸附剂是研究人员面临的一项科学挑战。在这项工作中，通过化学氧化法制备了一种聚吡咯-单宁酸纳米复合材料，并用作去除这些有毒染料的新型吸附剂。通过透射电子显微镜、扫描电子显微镜、X 射线衍射、傅里叶变换红外光谱和 Brunauer-Emmett-Teller 方法对合成的纳米复合材料进行了表征。研究了吸附剂剂量、温度、pH 值、染料初始浓度和接触时间等不同参数对吸附的影响。吸附与准二级动力学和 Langmuir 等温线模型一致。计算 ΔG°、ΔH° 和 ΔS° 以确定吸附的可行性。发现该吸附剂对 MO 染料的最大吸附容量为 204.08 mg/g，对 MB 染料的最大吸附容量为 217.39 mg/g。