The present study, for the first time, utilized 3,4-diaminobenzophenone (DABP)-functionalized Fe₃O₄/AC@SiO₂ (Fe₃O₄/AC@SiO₂@DABP) magnetic nanoparticles (MNPs) synthesized as a nanoadsorbent for enhancing adsorption and desorption capacity of gaseous benzene and toluene as volatile organic compounds (VOCs). The Fe₃O₄/AC@SiO₂@DABP MNPs used in adsorption and desorption of benzene and toluene were synthesized by the co-precipitation and sol-gel methods. The synthesized MNPs were characterized by SEM, FTIR, TGA/DTA, and BET surface area analysis. Moreover, the optimization of the process parameters, namely contact time, initial VOC concentration, and temperature, was performed by applying response surface methodology (RSM). Adsorption results demonstrated that the Fe₃O₄/AC@SiO₂@DABP MNPs had excellent adsorption capacity. The maximum adsorption capacities for benzene and toluene were found as 530.99 and 666.00 mg/g, respectively, under optimum process parameters (contact time 55.47 min, initial benzene concentration 17.57 ppm, and temperature 29.09 °C; and contact time 57.54 min, initial toluene concentration 17.83 ppm, and temperature 27.93 °C for benzene and toluene, respectively). In addition to the distinctive adsorptive behavior, the Fe₃O₄/AC@SiO₂@DABP MNPs exhibited a high reproducibility adsorption and desorption capacity. After the fifth adsorption and desorption cycles, the Fe₃O₄/AC@SiO₂@DABP MNPs retained 94.4% and 95.4% of its initial adsorption capacity for benzene and toluene, respectively. Kinetic and isotherm findings suggested that the adsorption mechanisms of benzene and toluene on the Fe₃O₄/AC@SiO₂@DABP MNPs were physical processes. The results indicated that the successfully synthesized Fe₃O₄/AC@SiO₂@DABP MNPs can be applied as an attractive, highly effective, reusable, and cost-effective adsorbent for the adsorption of VOC pollutants.

Graphical abstract

本研究首次利用3,4-二氨基二苯甲酮（DABP）-官能化的Fe ₃ O ₄ / AC @ SiO ₂（Fe ₃ O ₄ / AC @ SiO ₂ @DABP）磁性纳米颗粒（MNPs）合成了纳米吸附剂，用于提高气态苯和甲苯作为挥发性有机化合物（VOC）的吸附和解吸能力。Fe ₃ O ₄ / AC @ SiO ₂通过共沉淀和溶胶-凝胶法合成了用于苯和甲苯吸附和解吸的@DABP MNP。通过SEM，FTIR，TGA / DTA和BET表面积分析对合成的MNP进行表征。此外，通过应用响应表面方法（RSM）对工艺参数（即接触时间，初始VOC浓度和温度）进行了优化。吸附结果表明，Fe ₃ O ₄ / AC @ SiO ₂@DABP MNP具有出色的吸附能力。在最佳工艺参数下（接触时间55.47分钟，苯初始浓度17.57 ppm和温度29.09°C，接触时间57.54分钟，初始甲苯），在最佳工艺参数下，苯和甲苯的最大吸附容量分别为530.99和666.00 mg / g。苯和甲苯的浓度分别为17.83 ppm和27.93°C）。Fe ₃ O ₄ / AC @ SiO ₂ @DABP MNP除具有独特的吸附性能外，还具有很高的重现性吸附和解吸能力。经过第五次吸附和解吸循环后，Fe ₃ O ₄ / AC @ SiO ₂@DABP MNP分别保留了其最初对苯和甲苯的吸附能力的94.4％和95.4％。动力学和等温线研究结果表明，苯和甲苯在Fe ₃ O ₄ / AC @ SiO ₂ @DABP MNPs上的吸附机理是物理过程。结果表明，成功合成的Fe ₃ O ₄ / AC @ SiO ₂ @DABP MNPs可作为一种有吸引力，高效，可重复使用且具有成本效益的吸附剂用于VOC污染物的吸附。

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