Eragrostis plana Nees is an invasive species in Brazilian territory, known for its high levels of lignin, cellulose, and hemicellulose, making it a valuable raw material for activated carbon (AC) production. In this study, AC derived from Eragrostis plana Nees leaves was investigated as an adsorbent for silver nanoparticles (AgNPs). Kinetics, equilibrium, and thermodynamic assays were conducted to assess AgNPs adsorption onto AC. The AC exhibited a substantial surface area of 1030 m² g⁻¹ and demonstrated significant adsorption capacity for AgNPs. Both the pseudo-second-order and Langmuir models were found to best describe the kinetics and equilibrium of adsorption, with the highest adsorption capacity observed at 55 °C, reaching 140.19 mg g⁻¹ according to the Langmuir model. Thermodynamic analysis revealed an enthalpy change (∆H°) of 60.75 kJ mol⁻¹ and an entropy change (∆S°) of 0.2711 kJ mol⁻¹ K⁻¹, indicating that the adsorption process is spontaneous and endothermic. Additionally, the AgNPs/AC composite exhibited excellent catalytic activity in the 4-nitrophenol reduction, achieving a conversion rate of 97% within 10 min.

画眉草是巴西境内的一种入侵物种，以其高含量的木质素、纤维素和半纤维素而闻名，使其成为活性炭 (AC) 生产的宝贵原材料。在这项研究中，研究了源自画眉草叶的活性炭作为银纳米颗粒 (AgNP) 的吸附剂。进行动力学、平衡和热力学分析来评估 AgNPs 对 AC 的吸附。 AC 表现出 1030 m ²  g ^-1的大表面积，并表现出对 AgNP 的显着吸附能力。准二阶模型和 Langmuir 模型都可以最好地描述吸附动力学和平衡，根据 Langmuir 模型，在 55 °C 时观察到最高吸附容量，达到 140.19 mg g ^-1 。热力学分析显示，焓变（ΔH°）为60.75 kJ mol ^-1，熵变（ΔS°）为0.2711 kJ mol ^-1  K ^-1，表明吸附过程是自发的吸热过程。此外，AgNPs/AC复合材料在4-硝基苯酚还原中表现出优异的催化活性，在10分钟内实现了97%的转化率。