School of Energy and Power Engineering, Xi'an Jiaotong University, No. 28 Xianning West Rd, Xi'an, 710049, China.
Environ Sci Pollut Res Int. 2024 Feb;31(10):15209-15222. doi: 10.1007/s11356-024-32183-7. Epub 2024 Jan 30.
Utilizing cost-effective corn cob, zinc chloride-modified biochar was synthesized through one-step method for benzene adsorption from air. Study on impregnation ratio impact showed optimal benzene adsorption at ZnCl:CC ratio of 1.5:1, with capacity reaching 170.53 mg g. Characterization using BET, SEM, FTIR, and XPS was conducted. BET results indicated specific surface area of ZnBC at 1260.63 m g and maximum pore volume of 0.546 m g. SEM analysis revealed microporous-mesoporous structure in ZnBC, marking significant improvement over original biomass. DFT pore size distribution and FTIR analysis suggested post-modification dehydration and elimination reactions, leading to volatile compound release, functional group reduction, and pore widening. XPS analysis showed decrease in O = C-OH content with increased impregnation ratio, enhancing biochar's π-π electron diffusion for benzene. Langmuir isotherm and pseudo-second-order kinetic models effectively described experimental data, indicating multilayer benzene adsorption on biochar controlled by complex physicochemical adsorption and pore diffusion. Adsorption condition assessment, including adsorption temperature (20-120 ℃) and benzene concentration in inlet phase (159.73-383.36 mg L), was performed. Yoon-Nelson model fitting indicated adsorption site loss at higher temperatures and reduced capture ability due to increased adsorbate molecule kinetic energy. Higher adsorbate concentrations aided adsorption molecule diffusion to biochar surface and internal pores, increasing adsorption rate and shortening equilibrium time. Overall, zinc chloride-modified biochar facilitates benzene adsorption through pore filling and π-π interactions, with pore filling as primary mechanism. Produced biochar shows excellent regeneration properties and reusability.
利用具有成本效益的玉米芯，通过一步法合成了氯化锌改性生物炭，用于从空气中吸附苯。浸渍比影响的研究表明，在 ZnCl:CC 比为 1.5:1 时，苯的吸附效果最佳，吸附容量达到 170.53mg/g。采用 BET、SEM、FTIR 和 XPS 进行了表征。BET 结果表明 ZnBC 的比表面积为 1260.63m²/g，最大孔体积为 0.546m³/g。SEM 分析表明 ZnBC 具有微孔-介孔结构，与原始生物质相比有显著改善。DFT 孔径分布和 FTIR 分析表明，后修饰发生了脱水和消除反应，导致挥发性化合物的释放、官能团的减少和孔径的扩大。XPS 分析表明，随着浸渍比的增加，O = C-OH 含量减少，增强了生物炭对苯的 π-π 电子扩散。Langmuir 等温线和拟二级动力学模型有效地描述了实验数据，表明苯在生物炭上的吸附是多层的，受复杂的物理化学吸附和孔扩散控制。进行了吸附条件评估，包括吸附温度（20-120℃）和入口相中的苯浓度（159.73-383.36mg/L）。Yoon-Nelson 模型拟合表明，较高的温度会导致吸附位损失，吸附物分子的动能增加会降低捕获能力。较高的吸附物浓度有助于吸附分子扩散到生物炭表面和内部孔中，从而提高吸附速率并缩短平衡时间。总的来说，氯化锌改性生物炭通过孔填充和 π-π 相互作用促进苯的吸附，其中孔填充是主要机制。所制备的生物炭具有优异的再生性能和可重复使用性。
