Tin Dichalcogenides as Bifunctional Catalysts for Electrochemical Water Splitting in an Alkaline–Saline Medium

Electrochemical water splitting stands out as a viable method for generating sustainable hydrogen to address the energy needs of the future. This study evaluates mechanochemically synthesized tin dichalcogenides SnSe 2 and SnS 2 as bifunctional electrocatalysts. SnSe 2 and SnS 2 modified nickel foam (NF) electrodes show overpotential values of 378 and 307 mV for the oxygen evolution reaction and 124 and 103 mV for the hydrogen evolution reaction, respectively, at a current density of 10 mA cm −2 . Further, SnS 2 was tested in a symmetric two-electrode configuration, SnS 2 /NF||SnS 2 /NF, which delivers an overall cell voltage of 1.677 V at 10 mA cm −2 and stability over 35 h at 20 mA cm −2 . The findings highlight the promise of mechanochemically synthesized SnS 2 as an economical and effective bifunctional electrocatalyst for electrochemical water splitting. To explore the relevant performance in saline conditions, alkaline–saline model electrolytes are considered, wherein 0.5, 1.0, and 1.5 M NaCl + 1 M KOH electrolytes were tested, revealing that 1 M NaCl + 1 M KOH yields lower OER and HER overpotential values of 334 and 125 mV, and the SnS 2 /NF||SnS 2 /NF cell remained stable over 35 h.