Surfactant-assistant solvo/hydrothermal methods for preparation of nanoscale calcium aminodiphosphonates exhibiting high methylene blue adsorption affinity

Using surfactant-assistant solvo/hydrothermal methods, nanoscale calcium aminodiphosphonate species (CadP) with different morphologies, namely nanobelts, nanorods, and nano-networks have been synthesized. The final products with various morphologies have been obtained through controlled experimental conditions such as type of surfactant (with different concentrations), solvent, and base. Selected samples have been characterized by elemental analysis, FT-IR, TGA, XRD, SEM and TEM. Removal of a cationic/basic dye (methylene blue) from aqueous solution was investigated using synthesized nano-networks (CadP-N) as adsorbents. Effects of process parameters such as adsorbent morphology, adsorbent dose, pH, contact time, and initial dye concentration on the extent of methylene blue (MB) adsorption were investigated. Both the Langmuir and the Freundlich isotherms are fit to explain the MB adsorption on CadP-N. The maximum adsorption capacity of CadP-N was found to be 138.89 mg/g. Desorption experiments showed that CadP-N has the ability to remove adsorptive on the MB treatment for recycling use.