Easy-separative MoS2-glue sponges with high-efficient dye adsorption and excellent reusability for convenient water treatment

This study demonstrated high-efficient dye adsorption for wastewater using MoS 2 -glue sponge as an easy-separative and regenerative adsorbent. Flower-like molybdenum disulfide (MoS 2 ) nanopowders with rich polar edge sites were firstly synthesized by a facile one-pot hydrothermal method . Chemical and morphological features of MoS 2 nanoflowers were then examined by XRD , XPS , SEM and TEM . Afterwards, different concentrations of the MoS 2 -glue sponges with easy separability were successfully fabricated by a convenient two-step dip-coating method. The adsorption performance was estimated by the removal of Rhodamine B (RhB) dyes. The results proved that the maximum adsorption capacity of MoS 2 -glue sponge was 127.39 mg RhB/g product in 60 min. The RhB uptake behaviors can be well described by the Sips isotherm model and pseudo-second-order kinetic model , indicating a multilayer and chemical adsorption process. The adsorption mechanism proposed that the zwitterionic RhB molecules in aqueous solution would aggregate on the surface of negative charged MoS 2 in a head-to-tail way through electrostatic interaction . Furthermore, RhB dyes could desorb easily from MoS 2 -glue sponges when changing the polarity of solvent and the reusability experiment showed that the MoS 2 -3% glue sponge could be reused for 15 times with above 85.8% of the adsorption capacity retained. Thus, the novel MoS 2 -glue sponge is considered as a competitive adsorbent for treatment of dyestuff waste water.