Marine polysaccharide-derived multifunctional Fe single-atom catalysts and temperature-tolerant gel electrolyte for sustainable hydrogen production across a wide temperature range

Abstract

Advanced green hydrogen production systems typically rely on costly catalysts and face operational challenges in off-grid regions and extreme temperature environments. Herein, we propose a dual-purpose material strategy that synchronously converts marine polysaccharides into low-cost tri-functional electrocatalysts and weather-resistant gel electrolytes, enabling decarbonized hydrogen production in remote areas and under harsh temperature conditions. The constructed system demonstrated robust performance across temperatures ranging from −40 °C to 60 °C. A multiscale optimization approach modulates charge density at Fe active sites and metal-support interactions in Fe-based catalysts, achieving trifunctional activity (ORR: E_1/2 = 0.90 V; OER/HER: η = 261/172 mV@10 mA cm⁻²). Concurrently, hydrogen bond engineering transforms electrochemically inert agarose into highly compatible electrochemical interface gel electrolytes, enabling quasi-solid-state Zn-air batteries with extended operational temperature tolerance. This approach eliminates dependence on petroleum-derived materials while achieving carbon-neutral hydrogen production. Our work provides a mild, economical, and sustainable pathway for multidimensional marine biomass utilization and green hydrogen production.