Porous activated biocarbon from Ravenna grass was utilized as an adsorbent for the removal of 4-Nitrophenol from aqueous solution. Chemical activation process using potassium hydroxide was adopted for the activated biocarbon preparation. The essential features of the prepared adsorbent represented by BET surface area, pore volume and pHZPC were 919 m2g−1, 0.324 cm3g−1 and 8.1 respectively. SEM, FTIR, XRD and TGA analysis revealed the microcrystallite and porous structure of the synthesized biocarbon with abundant functional groups and high thermal stability. Batch adsorption tests were conducted for 4-Nitrophenol adsorption, and the optimum adsorbent dose, pH, initial 4-Nitrophenol concentration and contact time were found to be 0.5 g, 7, 400 mgL−1 and 40 minutes, respectively. The equilibrium isotherm study revealed the suitability of the Langmuir isotherm with a maximum adsorption capacity of 50.89 mg/g. The pseudo-second-order kinetic model well represented the adsorption kinetics data, while thermodynamics study indicated the spontaneity (ΔG<0) and endothermic nature (ΔH>0) of the adsorption of 4-Nitrophenol. Density functional theory (DFT) calculations performed at the B3LYP level indicated that the interaction of 4-Nitrophenol with pristine and functionalized activated biocarbon is favorable.

中文翻译：

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DFT法对活性炭吸附4-硝基苯酚的实验和理论结合研究

来自拉文纳草的多孔活性生物碳被用作吸附剂，用于从水溶液中去除 4-硝基苯酚。活性炭的制备采用氢氧化钾化学活化工艺。以 BET 表面积、孔体积和 pHZPC 为代表的所制备吸附剂的基本特征分别为 919 m2g-1、0.324 cm3g-1 和 8.1。SEM、FTIR、XRD 和 TGA 分析揭示了合成的生物碳的微晶和多孔结构，具有丰富的官能团和高热稳定性。对4-硝基苯酚吸附进行批量吸附试验，发现最佳吸附剂剂量、pH、初始4-硝基苯酚浓度和接触时间分别为0.5g、7、400mgL-1和40分钟。平衡等温线研究揭示了最大吸附容量为 50.89 毫克/克的朗缪尔等温线的适用性。拟二级动力学模型很好地代表了吸附动力学数据，而热力学研究表明 4-硝基苯酚的吸附具有自发性 (ΔG<0) 和吸热性 (ΔH>0)。在 B3LYP 水平上进行的密度泛函理论 (DFT) 计算表明，4-硝基苯酚与原始和功能化活性炭的相互作用是有利的。