Single-crystal oxygen-rich bismuth oxybromide nanosheets with highly exposed defective {10-1} facets for the selective oxidation of toluene under blue LED irradiation

Chenyu Li; Songting Gu; Yingxi Xiao; Xiaotong Lin; Xinyan Lin; Xiaoyang Zhao; Junmin Nan; Xin Xiao

doi:10.1016/j.jcis.2024.04.172

Single-crystal oxygen-rich bismuth oxybromide nanosheets with highly exposed defective {10-1} facets for the selective oxidation of toluene under blue LED irradiation

J Colloid Interface Sci. 2024 Aug 15:668:426-436. doi: 10.1016/j.jcis.2024.04.172. Epub 2024 Apr 24.

Authors

Chenyu Li¹, Songting Gu¹, Yingxi Xiao¹, Xiaotong Lin¹, Xinyan Lin¹, Xiaoyang Zhao², Junmin Nan³, Xin Xiao⁴

Affiliations

¹ School of Chemistry, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China.
² Department of Environmental Engineering, Henan Polytechnic Institute, Nanyang 473009, PR China.
³ School of Chemistry, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China. Electronic address: jmnan@scnu.edu.cn.
⁴ School of Chemistry, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China. Electronic address: xiaox@scnu.edu.cn.

PMID: 38688181
DOI: 10.1016/j.jcis.2024.04.172

Abstract

Reactive radicals are crucial for activating inert and low-polarity C(sp³)-H bonds for the fabrication of high value-added products. Herein, novel single-crystal oxygen-rich bismuth oxybromide nanosheets (Bi₄O₅Br₂ SCNs) with more than 85 % {10-1} facets exposure and oxygen defects were synthesized via a facile solvothermal route. The Bi₄O₅Br₂ SCNs demonstrated excellent photocatalytic performance in the selective oxidation of toluene under blue light. The yield of benzaldehyde was 1876.66 μmol g^-1 h^-1, with a selectivity of approximately 90 %. Compared to that of polycrystalline Bi₄O₅Br₂ nanosheets (Bi₄O₅Br₂ PCNs), the activity of Bi₄O₅Br₂ SCNs exhibit a 21-fold increase. Experimental studies and density functional theory (DFT) calculations have demonstrated that the defect Bi₄O₅Br₂ (10-1) facets exhibits exceptional adsorption properties for O₂ molecules. In addition, the single-crystal structure in the presence of surface defects significantly increases the separation and transport of photogenerated carriers, resulting in the effective activation of adsorbed O₂ into superoxide radicals (•O₂^-). Subsequently, the positively charged phenylmethyl H is readily linked to the negatively charged superoxide radical anion, thereby activating the CH bond. This study offers a fresh perspective and valuable insights into the development of efficient molecular oxygen-activated photocatalysts and their application in the selective catalytic conversion of aromatic C(sp³)-H bonds.

Keywords: Benzaldehyde; Highly exposed defective facets; Photocatalytic C(sp(3))-H bond activation; Selective oxidation of toluene; Single-crystal Bi(4)O(5)Br(2) nanosheets.