Sulfur-rich seaweed–derived carbon textured NiCo binary oxysulfide framework: A sustainable electrocatalyst for water splitting reaction

Attaining carbon neutrality requires sustainable hydrogen production through water electrolysis. The production of cost-effective electrocatalysts poses challenges, yet there is increasing interest in utilizing waste and naturally occurring materials for eco-friendly electrocatalysts. Seaweed-derived carbon has intrinsic sulfate groups that serve as metal ion anchoring sites, to facilitating strong interaction and uniform nucleation. The Cysteine and Methionine groups facilitate in-situ sulfur doping and the creation of metal oxy-sulfide phases during thermal treatment, producing a stable heterostructure electrocatalyst. The synthesised (NiCo 0.5 ) x O y S z @ SWDC exhibited a unique hierarchically porous structure with a large specific surface area with higher catalytic active sites. Consequently, the catalyst exhibits a decreased overpotential of 340 mV for the OER with a Tafel slope of 80 mV dec −1 and the HER overpotential of 280 mV at 10 mA cm −2 with a Tafel slope of 170 mV dec −1 in 1 M KOH. In a two-electrode configuration, the NiCo 0.5 -SWDC || NiCo 0.5 -SWDC electrolyzer exhibited efficient overall water-splitting activity, achieving a current density of 10 mA cm −2 at a cell voltage of only 1.61 V during 25 h of continuous electrolysis. This study offers an economical and sustainable approach to creating highly effective, scalable bifunctional catalysts.