Microbial-vulcanized organic-inorganic dual-modulated cobalt hydroxide for oxygen evolution reaction

Developing efficient chemical modification technologies for upgrading classic non-noble metal based electrocatalysts to further meet the demands of practical water electrolysis industry is of vital challenge. Here, we propose an organic-inorganic dual-modulation strategy to construct a cobalt hydroxide-based electrocatalyst, MEC-17, synthesized by an eco-friendly and facile microbial-mediated vulcanization method. This electrocatalyst, modified with both 2-methylimidazole and inorganic sulfur exhibits notable oxygen evolution reaction performance, achieving an overpotential of 285.6 ± 1.7 mV and exceeding 300 h of durability at a high current density of 1000 mA cm^-2. The operando characterizations and theoretical calculations reveal that sulfur dopant primarily shortens the Co-Co distances to support oxide path mechanism, while 2-methylimidazole plays a more critical role by modulating the d-band center of the Co sites, which optimizes intermediate adsorption for ensuring efficient O-O coupling. This work offers insights into the design of organic-inorganic hybrid electrocatalysts and contributes to understanding the origin of their electrocatalytic activities.