Hierarchical Ni-MOF/waste cotton fiber composite for continuous gas-phase benzene adsorption: experimental investigation and data-driven modeling

The efficient removal of volatile organic compounds (VOCs) using sustainable adsorbents remains an important environmental challenge. In this study, waste cotton fibers (WCFs) were used as a renewable support for the in situ growth of a hierarchical nickel-based metal–organic framework (Ni-MOF), producing a composite for gas- phase benzene (GPB) adsorption. Structural characterization confirmed the uniform growth of Ni-MOF crys tals on the cellulose fibers, increasing the BET surface area from 226.7 to 591.3 m 2 1 g 1 . Under optimal condi tions, the composite achieved a GPB removal efficiency (GPBRE) of 98.1% and an adsorption capacity of 243.7 mg g 2 , approximately 45% higher than that of Ni-MOF. Adsorption followed the pseudo-second-order (PSO) kinetic model (R = 0.997) and was spontaneous and exothermic. Response Surface Methodology (RSM) iden tified the optimum operating conditions, while an Artificial Neural Network (ANN) predicted adsorption per formance with high accuracy (R 2 = 0.994). The composite retained approximately 82% of its initial adsorption capacity after five regeneration cycles, demonstrating good regeneration stability. Therefore, the results high light WCFs as an effective support for Ni-MOF and provide a sustainable strategy for converting textile waste into high-value adsorbents for VOC removal.