Reduction of Transition-Metal Columbite-Tantalite as a Highly Efficient Electrocatalyst for Water Splitting

Patrick M Bacirhonde; Nelson Y Dzade; Carmen Chalony; Jeesoo Park; Eun-Suk Jeong; Emmanuel O Afranie; Sunny Lee; Cheol Sang Kim; Do-Hwan Kim; Chan Hee Park

doi:10.1021/acsami.1c21742

Reduction of Transition-Metal Columbite-Tantalite as a Highly Efficient Electrocatalyst for Water Splitting

ACS Appl Mater Interfaces. 2022 Apr 6;14(13):15090-15102. doi: 10.1021/acsami.1c21742. Epub 2022 Mar 24.

Authors

Patrick M Bacirhonde^{1

2

3}, Nelson Y Dzade^{4

5}, Carmen Chalony^{1

2}, Jeesoo Park^{1

2}, Eun-Suk Jeong⁶, Emmanuel O Afranie⁷, Sunny Lee^{1

2}, Cheol Sang Kim^{2

8}, Do-Hwan Kim^{6

9}, Chan Hee Park^{2

8}

Affiliations

¹ Department of Bionanosystem Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea.
² Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea.
³ Department of Geology and Mining Exploration, University of Goma, 204 Goma, Democratic Republic of Congo.
⁴ School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, Wales CF10 3AT, U.K.
⁵ Department of Energy and Mineral Engineering, Pennsylvania State University, University Park, State College, Pennsylvania 16802, United States.
⁶ Division of Science Education and Institute of Fusion Science, Jeonbuk National University, Jeonju, Jeonbuk 54896 Republic of Korea.
⁷ Department of Materials Science and Engineering, Chungnam National University, 99 Daehang-no, Yuseong-gu, Daejeon 305-764, Republic of Korea.
⁸ Division of Mechanical Design Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea.
⁹ Department of Energy Storage/Conversion Engineering of Graduate School, Jeonbuk National University, Jeonju, Jeollabuk-do 54896, Republic of Korea.

PMID: 35324159
DOI: 10.1021/acsami.1c21742

Abstract

We successfully report a liquid-liquid chemical reduction and hydrothermal synthesis of a highly stable columbite-tantalite electrocatalyst with remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in acidic media. The reduced Fe_0.79Mn_0.21Nb_0.16Ta_0.84O₆ (CTr) electrocatalyst shows a low overpotential of 84.23 mV at 10 mA cm^-2 and 103.7 achieved at 20 mA cm^-2 current density in situ for the HER and OER, respectively. The electrocatalyst also exhibited low Tafel slopes of 104.97 mV/dec for the HER and 57.67 mV/dec for the OER, verifying their rapid catalytic kinetics. The electrolyzer maintained a cell voltage of 1.5 V and potential-time stability close to that of Pt/C and RuO₂. Complementary first-principles density functional theory calculations identify the Mn sites as most active sites on the Fe_0.75Mn_0.25Ta_1.875Nb_0.125O₆ (100) surface, predicting a moderate Gibbs free energy of hydrogen adsorption (ΔG_H* ≈ 0.08 eV) and a low overpotential of η = 0.47 V. The |ΔGMn_H*| = 0.08 eV on the Fe_0.75Mn_0.25Ta_1.875Nb_0.125O₆ (100) surface is similar to that of the well-known and highly efficient Pt catalyst (|ΔGPt_H*| ≈ 0.09 eV).

Keywords: 3d−5d transition metals; cation vacancies; columbite-tantalite; electrocatalyst; ionic−electronic conductivity; liquid−liquid chemical reduction; oxygen vacancies; water splitting.