Unveiling selective nitrate reduction to ammonia with Co3O4 nanosheets/TiO2 nanobelt heterostructure catalyst

Xiaoya Fan; Chaoqun Ma; Donglin Zhao; Zhiqin Deng; Longcheng Zhang; Yan Wang; Yongsong Luo; Dongdong Zheng; Tingshuai Li; Jing Zhang; Shengjun Sun; Qipeng Lu; Xuping Sun

doi:10.1016/j.jcis.2022.10.050

Unveiling selective nitrate reduction to ammonia with Co₃O₄ nanosheets/TiO₂ nanobelt heterostructure catalyst

J Colloid Interface Sci. 2023 Jan 15;630(Pt A):714-720. doi: 10.1016/j.jcis.2022.10.050. Epub 2022 Oct 18.

Authors

Xiaoya Fan¹, Chaoqun Ma², Donglin Zhao¹, Zhiqin Deng¹, Longcheng Zhang¹, Yan Wang¹, Yongsong Luo¹, Dongdong Zheng¹, Tingshuai Li¹, Jing Zhang³, Shengjun Sun⁴, Qipeng Lu⁵, Xuping Sun⁶

Affiliations

¹ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China.
² School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, Beijing, China.
³ Interdisciplinary Materials Research Center, Institute for Advanced Study, Chengdu University, Chengdu 610106, China.
⁴ College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, Shandong, China.
⁵ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, Beijing, China. Electronic address: [email protected].
⁶ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China; College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, Shandong, China. Electronic address: [email protected].

PMID: 36274406
DOI: 10.1016/j.jcis.2022.10.050

Abstract

Electrochemical nitrate (NO₃^-) reduction reaction (NO₃RR) possesses two-pronged properties for sustainable ammonia (NH₃) synthesis and mitigating NO₃^- contamination in water. However, the sluggish kinetics for the direct eight-electron NO₃^--to-NH₃ conversion makes a formidable challenge to develop efficient electrocatalysts. Herein, we report a heterostructure of Co₃O₄ nanosheets decorated TiO₂ nanobelt array on titanium plate (Co₃O₄@TiO₂/TP) as an efficient NO₃RR electrocatalyst. Both experimental and density theory calculations reveal that the heterostructure of Co₃O₄@TiO₂ establishes a built-in electric field which can optimize the electron migration kinetics, as well as facilitate the adsorption and fixation of NO₃^- on the electrode surface, ensuring the selectivity to NH₃. As expected, the designed Co₃O₄@TiO₂/TP exhibits a remarkable Faradaic efficiency of 93.1 % and a remarkable NH₃ yield as high as 875 μmol h^-1 cm^-2, superior to Co₃O₄/TP and TiO₂/TP. Significantly, it also demonstrates strong electrochemical durability.

Keywords: Ambient ammonia synthesis; Co(3)O(4)@TiO(2) nanoarray; Density functional theory; Heterojunction; Nitrate reduction reaction.