Photocatalytic nitrogen fixation: Oxygen vacancy modified novel micro-nanosheet structure Bi2O2CO3 with band gap engineering

• Published in: Journal of colloid and interface science Vol. 583; pp. 499 - 509
• Main Authors: Feng, Yalan, Zhang, Zisheng, Zhao, Kai, Lin, Shuanglong, Li, Hong, Gao, Xin
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.02.2021
• Subjects: Active sites; ambient temperature; ammonia; Bi2O2CO3; energy; light; nanosheets; Nitrogen fixation; oxygen; Photocatalysis; Surface oxygen vacancies; Nitrogen fixation; Active sites; Photocatalysis; Bi2O2CO3; Surface oxygen vacancies
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/j.jcis.2020.09.089

[Display omitted] •Micro-nanosheet oxygen vacancy modified Bi2O2CO3 were synthesized.•Highly efficient photocatalytic nitrogen fixation activity and recycle stability.•N2 activation by joint effects of surface effect and surface oxygen vacancies.•Band gaps were consecutively tuned by artificial control of the content of surface oxygen vacancies. As a promising ammonia synthesis approach to replace the industrial Harber method, the biggest problem restricting photocatalytic nitrogen fixation is the suboptimal efficiency. Herein, novel surface oxygen vacancies modified micro-nanosheet structure Bi2O2CO3 (namely BOC/OV) were successfully synthesized via facile formation under room temperature. These defects-rich nanosheets exhibit outstanding performance for photocatalytic nitrogen fixation under visible light. The surface oxygen vacancies provide abundant active sites for molecular N2 activation, and the effect of scattered nanometer-size could facilitate the separation of photo-generated charges. Moreover, the energy band can be consecutively tuned with the accumulation of surface oxygen vacancies by lowering the conduction band position. Among all as-prepared samples, BOC/OV3 exhibited the highest NH4+ yield, reaching 1178 μmol·L−1·g−1·h−1, which is 10 times than that of pristine Bi2O2CO3. In this work, all samples synthesis and defects formation were conducted without requiring any secondary energy, which is of great significance for realizing green and efficient artificial ammonia synthesis.