SnS intercalated boronized Ni-ZIF heterostructures for overall electrolysis and energy storage applications

The rising demand for advanced energy technologies underscores the need for high-performance multifunctional electrocatalysts for energy conversion and storage. MOFs (Metal-Organic Frameworks), notably Ni-ZIF (Nickel Zeolite Imidazole Frameworks) have attracted interest in various electrocatalysis. However, limited stability and active sites hinder its use in water splitting and supercapacitors. Herein, we present the incorporation of tin sulfide (SnS) onto boronized Ni-ZIF (B:NiZIF) upon nickel foam to outperform in supercapacitor and alkaline water electrolysis applications. The SnS/B:NiZIF/NF showed reduced overpotentials for OER (oxygen evolution reaction) (290 mV @ 20 mA cm⁻²) and HER (hydrogen evolution reaction) (72 mV @ 20 mA cm⁻²) in 1.00 Mol KOH solution. The enhanced activity stems from empowered sulfur exposure over B:NiZIF and also due to interfacial electron transfer between SnS/B:NiZIF, as validated by X-ray photoelectron spectroscopy and X-ray diffraction. SnS/B:NiZIF achieved 10 mA cm⁻² at 1.54 V, demonstrating efficient electrolysis. In supercapacitor applications, SnS/B:NiZIF demonstrated superior specific capacitance and specific capacity of 2927.5 F g⁻¹ and 13470 mF/cm² respectively, at 1 mA cm⁻² due to the synergy between SnS and B:NiZIF/NF. The observed high electrode stability in water splitting/supercapacitors are attributed to the strong interfacial bonding between SnS and B:NiZIF.