Multifunctional Salt-Assisted Construction of Lignin-Derived Ru–Co Bimetal/Carbon Composites with Rich Nanointerface for Electrocatalytic Water Splitting

Abstract

Rational design of biomass-derived carbon nanocomposites as bifunctional catalysts of the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is of great significance for both the high-valued utilization of biomass waste and the practical application of water splitting. Herein, a novel multifunctional salt-assisted strategy consisting of surface/interface engineering is proposed to achieve a lignin-derived bifunctional catalysts of OER and HER using potassium hexacyanocobaltate (PHC) as the multifunctional modifying agent and lignin as the carbon precursor. PHC can not only induce Co-based components and nitrogen doping but also dramatically improve pore structure. Profiting from the surface-interface synergistic structures of Ru–Co multiple active components and hierarchical porous carbon support with high surface area, the RuCo-NC-120 catalyst shows superior activities toward OER and HER with the overpotentials of 242 and 52 mV at 10 mA cm–2, respectively. As a consequence, the RuCo-NC-120-based alkali electrolyzer only needs a cell voltage of 1.531 and 1.825 V to achieve 10 and 200 mA cm–2, respectively, and possesses excellent long-term stability. This study provides a novel strategy to effectively regulate the composition, morphology, and pore structure of the lignin-derived carbon, and it may open new avenues for high-value utilization of lignin.

Probing the evolution in catalytic graphitization of biomass-based materials for enduring energetic applications

“…Generally, combining two catalysts with complementary properties can lead to improved catalytic activity and selectivity. 14,64 Multi-catalyst systems, incorporating a combination of metal and non-metallic catalysts, are engineered for synergistic effects that can enhance catalytic performance and provide improved control over crystal growth and the nal carbon structure. This enables precise control over the graphitization process, inuencing factors such as crystal size, surface area, and conductivity.…”