Exploring Sustainable Hydrogen Production from Alkaline Fresh and Seawater Using Natural Ore Derived 2D Bi₂S₃

Water electrolysis for hydrogen, though widely studied, presents exciting opportunities for improvement beyond conventional energy and cost-intensive catalysts. Natural ores, being abundant and readily available, hold immense promise as sustainable sources of alternative energy materials. Here, this method offers a simple and low-cost route, not only to make 2D materials but also to develop electrocatalysts from earth-abundant ores. Synthesis of 2D Bi₂S₃ is demonstrated via Liquid phase exfoliation (LPE) of the naturally abundant bismuthinite ore. Sustainability of such 2D Bi₂S₃ is explored for hydrogen evolution reaction (HER) from alkaline fresh and simulated seawater. The exfoliated Bi₂S₃ exhibits an overpotential of 693 and 678 mV at 10 mA cm^{- 2} in alkaline fresh and simulated seawater with a durability up to 40 h. From Density Functional Theory (DFT) based First-principles calculations, sulfur sites are found to bind H-intermediates strongly in comparison with bismuth sites. Sustainability is further investigated by life cycle calculation. A lower carbon footprint of the 2D Bi₂S₃ catalyst is observed under both alkaline fresh (21.13 kg CO₂eq kg^-1 H₂) and simulated seawater (15.56 kg _CO2eq kg^-1 H₂). This work extends a sustainable strategy to utilize earth-abundant natural source for fabricating efficient and durable HER electrocatalysts for future fuel.