Realizing the synergy of interface engineering and surface reconstruction in Ni(OH)2 for superior water oxidation

摘要

Exploring cost-effective and stable electrocatalysts for the oxygen evolution reaction (OER) is of great importance to converting renewable electricity into fuels. Herein, we demonstrate the preparation of phytic acid-iron complex (PAFe) decorated Co3O4/Ni(OH)2 core-shell heterojunction using a hydrothermal-sol-vothermal combined with the typical coordination chemistry technique. The Co3O4 nanowires increase the electrical conductivity and inhibit the agglomeration of Ni(OH)2 nanosheets. The core-shell structure with a tightly contacted interface can regulate the interfacial electronic structure and enhance electron transfer ability. More importantly, the leach of PA under OER operation benefits the dissolution and re-adsorption of Fe species on the surface of the catalyst. The formed amorphous and active multi-metallic oxyhydroxides accelerate the catalytic reaction kinetics. As a result, the Co3O4/Ni(OH)2 @PAFe exhibits excellent OER performance with a low overpotential of 230 mV at 10 mA cm-2 (reduced by 84 mV compared with that of the original Ni(OH)2), a small Tafel slope of 43 mV dec-1, and prominent long-term durability. This research offers a new sight to enhance the catalytic performance of hydroxides and makes for future energy storage and conversion systems.

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