Bismuth-rich bismuth oxyiodide microspheres with abundant oxygen vacancies as an efficient photocatalyst for nitrogen fixation

• Published in: Dalton transactions : an international journal of inorganic chemistry 2020-07, Vol.49 (26), p.9123-9129
• Main Authors: Lan, Meng, Zheng, Nan, Dong, Xiaoli, Hua, Chenghe, Ma, Hongchao, Zhang, Xiufang
• Format: Article
• Language: English
• Subjects: Ammonia; Bismuth; Current carriers; Design defects; Hydrogen reduction; Light irradiation; Microspheres; Nitrogen; Nitrogenation; Noble metals; Orthorhombic phase; Photocatalysis; Photocatalysts; Vacancies
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d0dt01332c

Solar-driven reduction of dinitrogen (N 2 ) to ammonia (NH 3 ) is still challenging due to the highly stable N-N triple bond. Herein, orthorhombic phase H-Bi 5 O 7 I microspheres with abundant oxygen vacancies (OVs) were successfully prepared via a simple calcination and hydrogen reduction strategy. Based on the combined bismuth-rich strategy and the introduction of OVs in H-Bi 5 O 7 I, a remarkable photocatalytic nitrogen fixation performance was achieved under visible light irradiation in the absence of any organic scavengers or noble-metal cocatalysts. H-Bi 5 O 7 I exhibits an NH 4 + generation rate of 162.48 μmol g −1 h −1 , which is 2.0 and 7.4 times higher than that of Bi 5 O 7 I and BiOI. It is because H-Bi 5 O 7 I with abundant OVs has a more proper band gap, better electron capturing ability and more effective separation and transfer rate for the photogenerated charge carriers. This study may provide a new direction and useful insight for the design of defect assisted N 2 fixation photocatalysts. A combined bismuth-rich and defect introduction strategy was used to prepare the H-Bi 5 O 7 I with abundant oxygen vacancies, which can effectively yield ammonia under visible light without any organic scavengers or noble-metal cocatalysts.