Revealing the role of the 1T phase on the adsorption of organic dyes on MoS2 nanosheets

Asmaa M Omar; Ossama I Metwalli; Mohamed R Saber; Gomaa Khabiri; Mohamed E M Ali; Arafa Hassen; Mostafa M H Khalil; Ahmed A Maarouf; Ahmed S G Khalil

doi:10.1039/c9ra05427h

Revealing the role of the 1T phase on the adsorption of organic dyes on MoS₂ nanosheets

RSC Adv. 2019 Sep 9;9(49):28345-28356. doi: 10.1039/c9ra05427h.

Authors

Asmaa M Omar¹, Ossama I Metwalli¹, Mohamed R Saber², Gomaa Khabiri¹, Mohamed E M Ali³, Arafa Hassen¹, Mostafa M H Khalil⁴, Ahmed A Maarouf⁵, Ahmed S G Khalil¹

Affiliations

¹ Environmental and Smart Technology Group (ESTG), Physics Department, Faculty of Science, Fayoum University 63514 Fayoum Egypt asg05@fayoum.edu.eg.
² Chemistry Department, Faculty of Science, Fayoum University 63514 Fayoum Egypt.
³ Water Pollution Research Department, National Research Centre 33 El Bohouth St. P.O. 12622 Giza Egypt.
⁴ Chemistry Department, Faculty of Science, Ain Shams University Abbassia 11566 Cairo Egypt.
⁵ Department of Physics, IRMC, Imam Abdulrahman Bin Faisal University Saudia Arabia amaarouf@iau.edu.sa.

Abstract

Herein, different phases of MoS₂ nanosheets were synthesized, characterized and tested for dye removal from water. The influence of the MoS₂ phases as well as the 1T concentration on the adsorption performance of organic dyes MO, RhB and MB was deeply investigated. The results revealed that the 1T-rich MoS₂ nanosheets have superior adsorption performance compared to other 2H and 3R phases. The kinetic results of the adsorption process demonstrate that the experimental data followed the pseudo-second order equation. Meanwhile, the adsorption of dyes over the obtained materials was fitted with several isotherm models. The Langmuir model gives the best fitting to the experimental data with maximum a adsorption capacity of 787 mg g^-1. The obtained capacity is significantly higher than that of all previous reports for similar MoS₂ materials. Computational studies of the 2H and 1T/2H-MoS₂ phases showed that the structural defects present at the 1T/2H grain boundaries enhance the binding of hydroxide and carboxyl groups to the MoS₂ surface which in turn increase the adsorption properties of the 1T/2H-MoS₂ phase.