Hierarchical Microspheres of MoS₂ Nanosheets: Efficient and Regenerative Adsorbent for Removal of Water-Soluble Dyes

Abstract

This study demonstrates fast and efficient removal of dyes from the wastewater using nanostructural MoS 2 as a regenerative adsorbent. The hierarchical microspheres of MoS 2 nanosheets were prepared by one-step facile and scalable hydrothermal route using polyethylene glycol as a templating material. Chemical and morphological features of hierarchical microspheres of MoS 2 nanosheets were examined by XPS, FTIR, XRD, FESEM and HRTEM. The adsorption of a series of organic dyes using MoS 2 nanosheets was systematically investigated. The kinetic study illustrated that adsorption of methylene blue dye on to the MoS 2 nanosheets followed the pseudo second order model. The adsorption isotherm at the equilibrium was supported by Freundlich isotherm model. The hierarchical microspheres of MoS 2 nanosheets showed adsorption capacity as high as 297, 204, 216, 183, 146 mg.g -1 for methylene blue, malachite green, rhodamine 6G, fuchsin acid and congo red dyes, respectively. The high adsorption capacity was attributed to the hierarchical arrangement of MoS 2 nanosheets in the microscopic spheres, where dye molecules have very fast accessibility. Importantly, the hierarchical microspheres of MoS 2 nanosheets can be efficiently regenerated and reused for the dye adsorption of subsequent batch without compromising the adsorption capacity.

Edge‐Enriched Ultrathin MoS2 Embedded Yolk‐Shell TiO2 with Boosted Charge Transfer for Superior Photocatalytic H2 Evolution

“…Figure a shows the high‐resolution Mo 3d XPS spectra of MoS 2 , where two main peaks were observed at the binding energies of 232.5 and 229.3 eV, corresponding to the Mo 3p 3/2 and Mo 3p 5/2 core levels of the Mo 4+ species, respectively, which are also similar to values in previous reports . A shoulder signal at around 226.5 eV can be assigned to S(2s) . Similarly, sulfur species were also characterized from the XPS S 2p spectrum (Figure a, bottom).…”

Anchoring H3PW12O40 on aminopropylsilanized spinel‐type cobalt oxide (Co3O4‐SiPrNH2/H3PW12O40): A novel nanohybrid adsorbent for removing cationic organic dye pollutants from aqueous solutions

“…Figure S2 indicates the FT‐IR spectra of pristine Co 3 O 4 –SiPrNH 2 /PW 12 nanohybrid, MB, and the recovered Co 3 O 4 –SiPrNH 2 /PW 12 nanohybrid after adsorption of MB dye. The presence of characteristics peaks of MB at 1598 cm ‐1 (C=C aromatic ), 1390 cm ‐1 (=C−N aromatic ), and 1334 cm ‐1 (−C−N) confirmed the adsorption of MB dye on the surface of Co 3 O 4 –SiPrNH 2 /PW 12 . However, these bands are not seen in the pristine Co 3 O 4 –SiPrNH 2 /PW 12 nanohybrid.…”

Inorganic–organic nanohybrid of MoS2-PANI for advanced photocatalytic application

“…(1) V(L) represents the volume of the solution and W(g) is the amount of MoS 2 -PANI used for MB dye adsorption [29,30]. Pseudo first order represents a process which depends on Van der Waals interaction between the adsorbate (MB) and adsorbent (MoS 2 -PANI).…”

“…where k 2 is the second order rate constant [30]. Figure 10c shows the fitting results of pseudo second order model.…”