LAUSR

Abstract Permanganate ( M n O 4 − ) ions were adsorbed on the surface of MoS2 nanosheet and then reacted with it. In this work, effects of pH, temperature, initial M n O 4 − concentration and ionic strength on this process were studied. The adsorption sites of MoS2 were M o ( I V ) – S pairs located in its micropores (abbreviated as MI). Before starting reaction, MoS2 acted as a high capacity adsorbent for M n O 4 − ions at a certain time. Under various conditions, M n O 4 − ions were adsorbed on the surface of MoS2 during different time periods (20–180 ​min) and then reacted with it. The maximum adsorption capacity of M n O 4 − ions on MoS2 surface in water at 328 ​K was 368.3 ​mg ​g-1 (2.33 ​mmol ​g-1). Adsorption isotherms were analyzed by the ARIAN model and it was recognized that in the pH range of 1–11, adsorption isotherms were composed from regions I and II and Δ H values of the process for regions I and II in neutral water were 31.4 ​kJ ​mol-1 and 9.9 ​kJ ​mol-1, respectively. At pH ​= ​12, adsorption isotherm was only formed from region I. In the pH range of 1–12, after completion of adsorption process, reaction of adsorbed M n O 4 − ions with adsorbent obeyed ARIAN–Hinshelwood mechanism. In the pH range of 1–11, water molecules and at pH ​= ​12, O H − ions and water molecules acted as nucleophiles, respectively. Finally, MoS2 adsorbent was used for separation of C r 2 O 7 2 − and Ni2+ ions from M n O 4 − ions in water.