Partner: Youngseok Lee


Recent publications
1.Birhanu Bayissa G., Teshome Tufa L., Mahendra G., Lee Y., Fikadu Banti B., Nwaji Njoku N., You S., Lee J., Oxygen Vacancy Generation and Stabilization in Layered NiFeCo Double Hydroxide Nanosheets for a Highly Efficient Oxygen Evolution Reaction, ACS Applied Nano Materials, ISSN: 2574-0970, DOI: 10.1021/acsanm.4c01840, Vol.8, pp.A-K, 2024
Abstract:

Oxygen vacancy (Vo) is ubiquitous, playing a critical role in tuning the electronic configuration and optimizing the adsorption of adsorbates in the oxygen evolution reaction (OER) process. However, fine control over the density and stabilization of Vo is a big challenge in the highly oxidizing environment of OER. Herein, we have fabricated bulk NiFeCo (layered double hydroxide) LDHs via the hydrothermal method and exfoliated them into thin sheets rich with Vo using high-energy Ar-plasma. We doped fluoride to simultaneously modulate the charge distribution of surrounding atoms and stabilize Vo by taking advantage of the extremely high electronegativity and similar ion diameter to oxygen of fluoride. The material exhibited OER activity with a low overpotential of 200 mV at 10 mA cm–2 and a Tafel slope of 34.6 mV dec–1. Density functional theory (DFT) calculations support the claim that Vo and fluoride substantially increase NiFeCo LDH OER activity by modifying the electronic structures of the catalytically active sites.

Keywords:

Electrocatalyst, Double layered hydroxide, oxygen evolution reaction, oxygen vacancy, stabilization

Affiliations:
Birhanu Bayissa G.-other affiliation
Teshome Tufa L.-other affiliation
Mahendra G.-other affiliation
Lee Y.-other affiliation
Fikadu Banti B.-other affiliation
Nwaji Njoku N.-IPPT PAN
You S.-other affiliation
Lee J.-Lexington High School (US)