Preparation of NaNbO3 microcube with abundant oxygen vacancies and its high photocatalytic N2 fixation activity in the help of Pt nanoparticles

Jiayu Zhang; Lin Yue; Zhihao Zeng; Chunran Zhao; Linjiang Fang; Xin Hu; Hongjun Lin; Leihong Zhao; Yiming He

doi:10.1016/j.jcis.2023.01.049

Preparation of NaNbO₃ microcube with abundant oxygen vacancies and its high photocatalytic N₂ fixation activity in the help of Pt nanoparticles

J Colloid Interface Sci. 2023 Apr 15:636:480-491. doi: 10.1016/j.jcis.2023.01.049. Epub 2023 Jan 11.

Authors

Jiayu Zhang¹, Lin Yue¹, Zhihao Zeng¹, Chunran Zhao², Linjiang Fang³, Xin Hu¹, Hongjun Lin⁴, Leihong Zhao⁵, Yiming He⁶

Affiliations

¹ Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Yingbin Road 688, Jinhua 321004, China.
² Department of Materials Science and Engineering, Zhejiang Normal University, Yingbin Road 688, Jinhua 321004, China.
³ Department of Arts and Sciences, University of Washington, Seattle, WA 98195, USA.
⁴ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
⁵ Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Yingbin Road 688, Jinhua 321004, China. Electronic address: zhaoleihong@163.com.
⁶ Department of Materials Science and Engineering, Zhejiang Normal University, Yingbin Road 688, Jinhua 321004, China; Key Laboratory of Solid State Optoelectronic Devices of Zhejiang Province, Zhejiang Normal University, Yingbin Road 688, Jinhua 321004, China. Electronic address: hym@zjnu.cn.

PMID: 36652823
DOI: 10.1016/j.jcis.2023.01.049

Abstract

In this study, the photocatalytic N₂ immobilization performance of NaNbO₃ is enhanced via oxygen vacancy introduction and Pt loading. The designed Pt-loaded NaNbO₃ with rich oxygen defects (Pt/O-NaNbO₃) is synthesized by combining ion-exchange and photodeposition methods. Characterization result indicates that the O-NaNbO₃ has hollow microcube morphology and higher surface area than NaNbO₃. The introduced oxygen defects greatly affect the energy band structure. The band gap is slightly narrowed and the conduction band is raised, allowing O-NaNbO₃ to generate electrons with strong reducibility. Moreover, the oxygen defects reduced the work function of NaNbO₃, leading to increased charge separation in the bulk phase. The loaded Pt nanoparticles can further increase the surface charge separation via the formed Schottky barriers between Pt and O-NaNbO₃, which was thought to be the primary cause of the increased photocatalytic activity. Additionally, the oxygen vacancies and metal Pt also contribute to the adsorption and activation of N₂. Under the combined effect of the above changes, Pt/O-NaNbO₃ presents much higher photoactivity than NaNbO₃. The optimized NH₃ production rate reaches 293.3 μmol/L g^-1h^-1 under simulated solar light, which is approximately 2.2 and 20.2 times higher than that of O-NaNbO₃ and NaNbO₃, respectively. This research offers a successful illustration of how to improve photocatalytic N₂ fixation and may shed some light on how to design and construct efficient photocatalysts by combining several techniques.

Keywords: Charge separation; NaNbO(3); Oxygen vacancy; Photocatalytic N(2) fixation; Pt.