Nano-perovskites of La with Mn or Fe cations were prepared by the Pechini method. The products were characterized by FT-IR, TGA/DTA, XRD, FESEM, BET, and AFM analysis. The degradation efficiency of an acidic solution of anionic, cationic and neutral azo or anthraquinone dyes was investigated in the presence of LaMn(Fe)O₃ and LaFeMn_0.5O₃ nanoperovskites without any external reagents under dark. The results reveal that degradation efficiency follows the order of LaMnO_3.125 > LaFeMn_0.5O₃ > LaFeO₃. Compared with pure LaFeO₃, the LaFeMn_0.5O₃ sample exhibits an enhanced adsorption capability and consequently catalytic performance. The key parameters such as catalyst type, dye initial concentration and reaction time on the degradation efficiency were optimized using response surface methodology (RSM) based on historical data design. The R², F-value, and p-value of the fitted quadratic model were obtained 0.9822, 315.51, and smaller than 0.0001, respectively; showing the significance and adequacy of the model. The Langmuir and Freundlich isotherms were utilized to fit the experimental data. The kinetic of degradation have been investigated with the use of pseudo-first-order and -second-order models. The isotherm and kinetic results reveal that each type of dye adsorb differently and need to study separately. Finally, the proposed catalysts outperformed similar catalysts in the degradation of organic dyes.

中文翻译：

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使用LaMn（Fe）O 3和LaFeMn 0.5 O 3纳米钙钛矿去除各种纺织染料；RSM优化，等温线和动力学研究

通过Pechini方法制备了具有Mn或Fe阳离子的La纳米钙钛矿。通过FT-IR，TGA / DTA，XRD，FESEM，BET和AFM分析对产品进行表征。在黑暗中，在没有任何外部试剂的情况下，在存在LaMn（Fe）O ₃和LaFeMn _0.5 O ₃纳米钙钛矿的情况下，研究了阴离子，阳离子和中性偶氮或蒽醌染料的酸性溶液的降解效率。结果表明，降解效率依次为LaMnO _3.125  > LaFeMn _0.5 O ₃  > LaFeO ₃。与纯LaFeO ₃相比，LaFeMn _0.5 O ₃样品具有增强的吸附能力，因此具有催化性能。基于历史数据设计，使用响应表面方法（RSM）优化了关键参数，如催化剂类型，染料初始浓度和反应时间对降解效率的影响。R ²拟合二次模型的，F值和p值分别为0.9822、315.51和小于0.0001；显示该模型的重要性和充分性。利用Langmuir和Freundlich等温线拟合实验数据。已经使用伪一级和二级模型研究了降解动力学。等温线和动力学结果表明，每种染料的吸附方式不同，需要分别研究。最后，所提出的催化剂在有机染料的降解方面胜过类似的催化剂。