Acid green crystal-based synthesis of polyaniline hollow nanotubes for the adsorption of anionic and cationic dyes.

In this article, acid green (AG) dye played a dual pivotal role. The first role is as a structure-guiding agent and a soft template for the acid-free synthesis of polyaniline hollow nanotubes (PANI-HNTs) while the second role is as a target dye to be removed as a model of anionic dyes, alongside methylene blue (MB) as a model of cationic dyes. After characterization using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms (BET), and UV-visible absorption spectroscopy techniques, the prepared PANI-HNTs were exploited for the adsorption of basic MB dye and acidic AG dye from aqueous media.