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Mo‐/Co‐N‐C Hybrid Nanosheets Oriented on Hierarchical Nanoporous Cu as Versatile Electrocatalysts for Efficient Water Splitting
Author(s) -
Shi Hang,
Dai TianYi,
Wan WuBin,
Wen Zi,
Lang XingYou,
Jiang Qing
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202102285
Subject(s) - overpotential , tafel equation , electrocatalyst , materials science , oxygen evolution , nanoporous , water splitting , bifunctional , chemical engineering , electrochemistry , electrolysis of water , electrolyte , inorganic chemistry , catalysis , nanomaterial based catalyst , electrolysis , nanotechnology , electrode , chemistry , organic chemistry , nanoparticle , photocatalysis , engineering
Designing robust and cost‐effective electrocatalysts based on Earth‐abundant elements is crucial for large‐scale hydrogen production through electrochemical water splitting. Here, nitrogen‐doped carbon engrafted Mo 2 N/CoN hybrid nanosheets that are seamlessly oriented on hierarchical nanoporous Cu scaffold (Mo‐/Co‐N‐C/Cu), as highly efficient electrocatalysts for alkaline hydrogen evolution reaction are reported. The constituent heterostructured Mo 2 N/CoN nanosheets work as bifunctional electroactive sites for both water dissociation and adsorption/desorption of hydrogen intermediates while the nitrogen‐doped carbon bridges electron transfers between electroactive sites and interconnective Cu current collectors by making use of Mo‐/Co‐N‐C bonds and intimate C/Cu contacts at interfaces. As a consequence of unique architecture having electroactive sites to be sufficiently accessible, self‐supported nanoporous Mo‐/Co‐N‐C/Cu hybrid electrodes exhibit outstanding electrocatalysis in 1 m KOH, with a negligible onset overpotential and a low Tafel slope of 47 mV dec −1 . They only take overpotential of as low as 230 mV to reach current density of 1000 mA cm −2 . When coupled with their electro‐oxidized derivatives that mediate efficiently the oxygen evolution reaction, the alkaline water electrolyzer can achieve ≈100 mA cm −2 at 1.622 V in 1 m KOH electrolyte, ≈0.343 V lower than the device constructed with commercially available Pt/C and Ir/C nanocatalysts immobilized on nanoporous Cu electrodes.