Fabrication of zirconium metal-organic-framework/poly triazine-phosphanimine nanocomposite for dye adsorption from contaminated water: Isotherms and kinetics models

Today, academia and industries are seeking some efficient adsorbents to cope with the increasing water contamination. This study aims to synthesize a hybrid material made of triazine-phosphanimine poly-meric organic porous polymer (TPA-POP) and UiO-66-NH2, followed by its characterization and examina-tion of its adsorption capacity. To this end, a central composite design (CCD) was applied to diminish the number of reaction parameters (i.e., adsorbent concentration, temperature, and initial pH) on removing the basic blue 41 (BB41). The results showed that BB41 was entirely adsorbed within 60 min by the meso-porous UiO-66-NH2 /TPA-POP nanostructure. In addition, the pseudo-second-order (PSO) model was iden-tified as the optimum formula to fit the kinetics information. This study revealed that film diffusion and adsorption are rate-limiting stages to remove the dyes. A Langmuir isotherm was applied to fit the equi-librium data, using which the highest equilibrium adsorption was calculated to be 260.7 mg/g. N 2 desorp-tion/adsorption isotherms of the UiO-66-NH2/TPA-POP and UiO-66-NH2 represent a type-I isotherm. The reduction in BET surface area from 918.7 m 2 g -1 (UiO-66-NH2) to 423 m 2 g -1 (hybrid material) might be explained by the hydrogen bonding between the TPA-POP and UiO-66-NH2. These interactions result in the small liquid nitrogen diffusivity into the hybrid network, thereby shrinking the BET surface area. Eventually, we recycled the adsorbent for 7 cycles to adsorb BB41 dye with no remarkable activity loss. (c) 2022 Elsevier B.V. All rights reserved.