Atomically isolated Sb(CN)3 on sp2-c-COFs with balanced hydrophilic and oleophilic sites for photocatalytic C-H activation

Zhenyuan Teng; Zhenzong Zhang; Hongbin Yang; Qitao Zhang; Teruhisa Ohno; Chenliang Su

doi:10.1126/sciadv.adl5432

Atomically isolated Sb(CN)₃ on sp²-c-COFs with balanced hydrophilic and oleophilic sites for photocatalytic C-H activation

Sci Adv. 2024 Feb 2;10(5):eadl5432. doi: 10.1126/sciadv.adl5432. Epub 2024 Jan 31.

Authors

Zhenyuan Teng^{1

2}, Zhenzong Zhang³, Hongbin Yang⁴, Qitao Zhang^{1

5}, Teruhisa Ohno², Chenliang Su^{1

5}

Affiliations

¹ State Key Laboratory of Radio Frequency Heterogeneous Integration, Shenzhen University, Shenzhen 518060, China.
² Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu 804-8550, Japan.
³ College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300350, China.
⁴ Institute for Materials Science and Devices, Suzhou University of Science and Technology, Suzhou 215011, China.
⁵ International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.

Abstract

Activation of carbon-hydrogen (C-H) bonds is of utmost importance for the synthesis of vital molecules. Toward achieving efficient photocatalytic C-H activation, our investigation revealed that incorporating hydrophilic C≡N-Sb(CN)₃ sites into hydrophobic sp² carbon-conjugated covalent organic frameworks (sp²-c-COFs) had a dual effect: It simultaneously enhanced charge separation and improved generation of polar reactive oxygen species. Detailed spectroscopy measurements and simulations showed that C≡N-Sb(CN)₃ primarily functioned as water capture sites, which were not directly involved in photocatalysis. However, the potent interaction between water molecules and the Sb(CN)₃-modified framework notably enhanced charge dynamics in hydrophobic sp²-c-COFs. The reactive species ·O₂^- and ·OH (ad) subsequently combined with benzyl radical, leading to the formation of benzaldehyde, benzyl alcohol, and lastly benzyl benzoate. Notably, the Sb(CN)₃-modified sp²-c-COFs exhibited a 54-fold improvement in reaction rate as compared to pristine sp²-c-COFs, which achieved a remarkable 68% conversion rate for toluene and an 80% selectivity for benzyl benzoate.