Scalable and controllable synthesis of atomic metal electrocatalysts assisted by an egg-box in alginate

Research output: Contribution to journalArticlepeer-review

Authors

  • Lijie Zhang
  • Tongchao Liu
  • Ning Chen
  • Yi Jia
  • Xianfeng Yang
  • Yanzhi Xia
  • Dongjiang Yang
  • Xiangdong Yao

Colleges, School and Institutes

External organisations

  • Qingdao University
  • Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
  • School of Electronic and Computer Engineering, Peking University, Shenzhen Graduate School
  • Saskatoon S7N 0X4
  • South China University of Technology
  • Queensland Micro- and Nanotechnology Centre
  • Collaborative Innovation Center of Marine Biobased Fibers and Ecological textiles
  • Canadian Light Source, 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 2V3

Abstract

Herein, a general strategy is developed to synthesize atomic metal catalysts using sustainable and earth-abundant sodium alginate (Na-Alg), a common seaweed extract, as a precursor. The “egg-box” structure in Na-Alg after ion-exchange with metal cations (Zn2+, Co2+, Ni2+, Cu2+, etc.) is the key to achieve a scalable and controllable synthesis of highly dispersed atomic metals. For instance, atomic Co, Ni and Cu have been successfully synthesized using this method. As a representative, the as-synthesized atomically dispersed Co on reduced graphene oxide (A-Co/r-GO) can reach a maximum metal loading of 3.6 wt%, showing outstanding catalytic activity and stability for the oxygen reduction reaction (ORR) with a half-wave potential (E1/2) of 0.842 V vs. RHE that is more positive than that of 20 wt% Pt/C (0.827 V vs. RHE) in alkaline solutions. The A-Co/r-GO catalyzed zinc-air batteries (ZABs) outperform Pt/C-based ZABs in the aspects of discharge voltage and specific zinc capacity, and can work robustly for more than 250 h with negligible voltage loss with refueling the Zn anode and KOH electrolyte periodically. This work opens up a new strategy for a general, practical and scalable synthesis of atomic metal catalysts at very low cost.

Details

Original languageEnglish
Number of pages9
JournalJournal of Materials Chemistry A
Early online date11 Sep 2018
Publication statusE-pub ahead of print - 11 Sep 2018