Sequential self-reconstruction of localized Mo species in hierarchical carbon/Co-Mo oxide heterostructures for boosting alkaline hydrogen evolution kinetics and durability

Quan Quan, Xiuming Bu, Dong Chen, Fei Wang, Xiaolin Kang, Wei Wang, You Meng, Senpo Yip, Chuntai Liu, Johnny C. Ho

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

Surface self-reconstruction processes in alkaline hydrogen evolution reaction (HER), especially regarding the explicit structure-activity relationships, remain elusive. Here, we first design a hierarchical Co@NCNT/CoMoOx precatalyst constituted by defective CoMoOx nanosheets grafted with flexible Co@NCNT arrays, followed by a delicate anodic treatment for fast dissolution balance. Benefiting from the multi-level Co@NCNT arrays as a stable micro-environment, the resultant Co@NCNT/CoMoyOx displays excellent electrocatalytic activity with a low overpotential of 195 mV at -100 mA cm-2 and stable 600 h operation for the HER in alkaline media, including natural seawater, which is better than most reported carbon/transition metal-based catalysts. In situ Raman analyses disclose a local high-resolution self-reconstruction evolution of localized Mo species at controllable negative potentials. Density functional theory calculations further demonstrate that the ultimate Mo-Mo surface state accelerates reaction kinetics to promote H2 generation in alkaline media. Our findings provide a unique insight into the mechanism of the structural evolution in the alkaline HER process to pave a new avenue guiding the design of durable and efficient catalysts.

Original languageEnglish
Pages (from-to)3953-3962
Number of pages10
JournalJournal of Materials Chemistry A
Volume10
Issue number8
DOIs
Publication statusPublished - Feb 28 2022

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Renewable Energy, Sustainability and the Environment
  • General Materials Science

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