Adsorption behavior of hydrophilic carbon nanotube freestanding film with high-efficiency water purification

Abstract

Carbon nanotube film composed of high permeability and specific surface area is desirable as a freestanding filtration to remove contaminants from wastewater. Herein, a porous hydrophilic carbon nanotube film (H-CNT) was prepared via a floating catalyst chemical vapor deposition and thermal treatment methods. The as-prepared film displayed superior permeability of 845.86 L m⁻² h⁻¹ bar⁻¹ and stable water flux in acid and alkali water environment. Notably, the H-CNT film is capable of efficiently partitioning oil-water emulsions and capturing water-soluble organic dyes, achieving separation and adsorption efficiencies exceeding 95%. In addition, the regression results showed that the adsorption kinetics were the combination of pseudo-first-order model and pseudo-second-order model. Moreover, the intraparticle diffusion model shows excellent concordance of experimental results. Our study reveals the interface interaction between five different organic dyes and H-CNTs for the absorption enhancement. The fabricated multifunctional H-CNT film shows promise regarding the purification of oil-polluted wastewater and the capture of water-soluble organic contaminants, potentially offering a novel approach to wastewater remediation.