Coupling of Nickel Boride and Ni(OH)2 Nanosheets with Hierarchical Interconnected Conductive Porous Structure Synergizes the Oxygen Evolution Reaction

• Published in: ChemCatChem 2018-10, Vol.10 (20), p.4555-4561
• Main Authors: Liang, Xiaoguang, Dong, Ruoting, Li, Dapan, Bu, Xiuming, Li, Fangzhou, Shu, Lei, Wei, Renjie, Ho, Johnny C.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Coupling; Electrocatalysts; hierarchical hybridization; Metal foams; Nanoparticles; Nanosheets; Nanostructure; Ni(OH)2 nanosheets; Nickel compounds; Ni−B nanoparticles; oxygen evolution reaction; Oxygen evolution reactions; Slope stability; Structural hierarchy; synergistic effects; Transition metals; Water splitting
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201800993

Earth‐abundant and highly‐efficient electrocatalysts for oxygen evolution reaction (OER) are urgently desired to realize the large‐scale storage and conversion of renewable energies. In this work, we develop a hierarchical porous electrocatalyst structure utilizing Ni(OH)2 nanosheets directly synthesized on Ni foam as the conductive and interconnected supports. By coupling with amorphous Ni−B nanoparticles, this hybrid catalyst exhibits dramatically enhanced electrocatalytic activities and durabilities towards OER. In specific, along with the optimized Ni−B loading, this catalyst requires only an impressively small overpotential of 300 mV to drive a current density of 100 mA cm−2 for oxygen evolution in 1 M KOH electrolyte. Meanwhile, it also yields a small Tafel slope of 49 mV dec−1 and a superior long‐term stability. All these results evidently indicate that the hierarchical hybridization of Ni−B with Ni(OH)2 on Ni foam can effectively synergize the oxygen evolution, opening up a new vista for designing high‐performance transition metal‐based nanostructures in the field of electrochemical water splitting. A hierarchical porous electrocatalyst structure utilizing Ni(OH)2 nanosheets directly synthesized on Ni foam as the conductive and interconnected supports is developed for the deposition of Ni−B nanoparticles by using the facile dip‐coating method. This synergistic hybrid electrocatalyst system configured of Ni−B nanoparticles, Ni(OH)2 nanosheets and Ni foam can exhibit dramatically electrocatalytic activities and superior long‐term stabilities towards oxygen evolution reaction.