MoS2@MIL-53 (Ni) nanocomposite for water splitting and water remediation through real time effluent treatment

Abstract

A novel molybdenum disulfide@ materials institute of Lavoisier (MoS2@MIL-53 (Ni)) hetero-structure material has been designed to act as a hydrogen/oxygen generator and as a water remediation agent. Two-dimensional layered MoS2@MIL-53 (Ni) nanocomposites were prepared through the hydrothermal method. Flower and layered morphology were observed for MoS2, and MIL-53 (Ni), respectively in the field emission scanning electron microscopy (FESEM) images. The MoS2@MIL-53 (Ni) nanocomposite demonstrated a high dye degradation efficiency of ∼98 % and ∼96 % for Rhodamine B (RhB) and bodactive blue (BAB) within 80 minutes of time duration, respectively. In the case of untreated textile industrial effluent (TIE), the nanocomposite achieved an efficiency of around 86 % over a period of 9 hours. The ultraviolet-visible absorption spectra of RhB, BAB, and TIE displayed peaks at ∼565 nm, 665 nm, and 530 nm, respectively. Additionally, the nanocomposite exhibited excellent stability over five cycles when tested against RhB. During hydrogen evolution reaction (HER), MoS2@MIL-53 (Ni) nanocomposite showed a Tafel slope of 105 mV/decade and overpotential of −0.073 V vs. RHE. Similarly, oxygen evolution reaction (OER) studies exhibited a reduced over potential at 0.49 V vs. RHE @ 10 mA/cm2 and the Tafel slope was calculated to be 42 mV/decade. Further, the chronoamperometry analysis of MoS2@MIL-53 (Ni) confirmed that the sample exhibited relatively good stability with respect to both HER and OER analysis for 24 hours. This is indicative of MoS2@MIL-53 (Ni)’s structural stability and its strong electrocatalytic activity.