A novel method for engineering active sites through in-situ and chemical deposition: Robust Ni3S2/MoS2/WS2 heterostructures for efficient water splitting in an alkaline medium

• Published in: International journal of hydrogen energy 2024-11, Vol.92, p.186-198
• Main Authors: Duraisamy, Prakash, Mummoorthi, Geerthana, Jayaram, Archana, Easwaran, Senthil Kumar, Mani, Navaneethan
• Format: Article
• Language: English
• Subjects: Bifunctional catalysts; Binder-free; Heterostructures; Ternary transition metal sulphides; Turnover frequency
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.09.337

To develop compact and efficient electrolysers, use a bi-functional electrocatalysts capable of performing both the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) at the same temperature, pressure, and pH. To develop ternary transition metal sulphides for OER and HER with superior performance. Herein, reported a sheet-like heterostructures electrode made of was fabricated on nickel foam using a simple hydrothermal method. The surface morphology and electrochemical active sites of the binder-free NMWS(1:1) heterostructures bi-functional catalyst were analysed in a 1.0 M KOH electrolyte medium to attain a lower overpotential for both OER (290 mV @ 10 mA cm−2) and HER (165 mV @ 10 mA cm−2). Electrochemical NMWS (1:1) studies show that the purported efficiencies are due to increased oxygen vacancies, interfacial bonds, and surface sulfur sites in the heterostructures were analysed through XPS, and HR-TEM. Furthermore, a dual-electrode in an electrolyser cell, the proposed heterostructures electrode achieved a current density of 10 mA cm−2 yet retained a remarkably low cell voltage of 1.73 V. The Ni3S2/MoS2/WS2 heterostructures stabilizes, which helps maintain LSV's low current degradation rate (CDR). The efficient water splitting has been calculated using turnover frequency and Tafel plot. [Display omitted] •Insitu growth of Ni3S2 and Chemical deposition of MoS2, WS2 in NMWS(1:1).•A bifunctional catalyst in an electrolyser cell with a low cell voltage of 1.733 V.•NMWS (1:1) with a small overpotential of ∼290 mV for OER, HER as ∼165 mV @ 10 mA cm 2.•Tafel plot explain the lowest active site for HER (77 mV dec−1) and OER (97 mV dec−1).•The turnover frequency for OER of about 55.11 s−1 at 1.62 RHE.