MOFs-derived plum-blossom-like junction In/In2O3@C as an efficient nitrogen fixation photocatalyst: Insight into the active site of the In3+ around oxygen vacancy

Mengyao Tan; Xiaoman Li; Senda Su; Linghu Meng; Shengbo Yuan; Yingying Wang; Zhenyu Liu; Min Luo

doi:10.1016/j.jcis.2023.01.116

MOFs-derived plum-blossom-like junction In/In₂O₃@C as an efficient nitrogen fixation photocatalyst: Insight into the active site of the In³⁺ around oxygen vacancy

J Colloid Interface Sci. 2023 May 15:638:263-273. doi: 10.1016/j.jcis.2023.01.116. Epub 2023 Jan 27.

Authors

Mengyao Tan¹, Xiaoman Li², Senda Su¹, Linghu Meng¹, Shengbo Yuan¹, Yingying Wang¹, Zhenyu Liu¹, Min Luo³

Affiliations

¹ State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, China.
² State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, China. Electronic address: lixm2017@nxu.edu.cn.
³ State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, China. Electronic address: luominjy@nxu.edu.cn.

PMID: 36738549
DOI: 10.1016/j.jcis.2023.01.116

Abstract

Nitrogen activation with low-cost, visible-light-driven photocatalysts continues to be a major challenge. Since the discovery of biological nitrogen fixation, multi-component systems have achieved higher efficiency due to the synergistic effects, thus one of the challenges has been distinguishing the active sites in multi-component catalysts. In this study, we report the photocatalysts of In/In₂O₃@C with plume-blossom-like junction structure obtained by one-step roasting of MIL-68-In. The "branch" is carbon for supporting and protecting the structure, and the "blossom" is In/In₂O₃ for the activation and reduction of N₂, which form an efficient photocatalyst for nitrogen fixation reaction with the performance of 51.83 μmol h^-1 g^-1. Experimental studies and DFT calculations revealed the active site of the catalyst for nitrogen fixation reaction is the In³⁺ around the oxygen vacancy in In₂O₃. More importantly, the elemental In forms the Schottky barrier with In₂O₃ in the catalyst, which can generate a built-in electric field to form charge transfer channels during the photocatalytic activity, not only broadens the light absorption range of the material, but also exhibits excellent metal conductivity.

Keywords: Active sites; Ammonia synthesis; In/In(2)O(3)@C; Oxygen vacancies; Photocatalysis.