Electron-rich Au nanocrystals/Co3O4 interface for enhanced electrochemical nitrate reduction into ammonia.

Maolin Zhang, Kepeng Song, Chen Liu, Zedong Zhang, Wen-Qing He, Hao Huang, Jialei Liu

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Solar-driven electrochemical NO3- reduction reaction (NO3-RR) is a clean and sustainable strategy that can convert pollutant NO3- in wastewater to value-added NH3. In recent years, cobalt oxides-based catalysts have shown their intrinsic catalytic properties toward NO3-RR but still have room for improvement through catalyst design. Coupling metal oxides with noble metal has been demonstrated to improve electrochemical catalytic efficiency. Here, we use Au species to tune the surface structure of Co3O4 and improve the efficiency of NO3-RR to NH3. The obtained Au nanocrystals-Co3O4 catalyst exhibited an onset potential of 0.54 V vs RHE, NH3 yield rate of 27.86 µg/h·cm2, and Faradaic efficiency (FE) of 83.1% at 0.437 V vs RHE in an H-cell, which is much higher than Au small species (Au clusters or single atoms)-Co3O4 (15.12 µg/h·cm2) and pure Co3O4 (11.38 µg/h·cm2), respectively. Combined experiments with theory calculations, we attributed the enhanced performance of Au nanocrystals-Co3O4 to the reduced energy barrier of *NO hydrogenation to the *NHO and suppression of HER, which originated from the charge transfer from Au to Co3O4. Using an amorphous silicon triple-junction (a-Si TJ) as the solar cell and an anion exchange membrane electrolyzer (AME), an unassisted solar-driven NO3-RR to NH3 prototype was realized with a yield rate of 4.65 mg/h and FE of 92.1%.
Original languageEnglish (US)
Pages (from-to)193-202
Number of pages10
JournalJournal of colloid and interface science
Volume650
DOIs
StatePublished - Jul 2 2023

Bibliographical note

KAUST Repository Item: Exported on 2023-07-06
Acknowledgements: This work was supported by National Natural Science Foundation of China (No.22206204) and the King Abdullah University of Science and Technology (KAUST).

ASJC Scopus subject areas

  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry
  • Electronic, Optical and Magnetic Materials

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