Acta Phys. -Chim. Sin. ›› 2024, Vol. 40 ›› Issue (12): 2405005.doi: 10.3866/PKU.WHXB202405005

Special Issue: Solar fuel preparation

• ARTICLE • Previous Articles     Next Articles

Modulating NH2 Lewis Basicity in CTF-NH2 through Donor-Acceptor Groups for Optimizing Photocatalytic Water Splitting

Zhao Lu1, Hu Lv2, Qinzhuang Liu3, Zhongliao Wang3,*()   

  1. 1 HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen 518000, Guangdong Province, China
    2 School of Construction Engineering, Shenzhen Polytechnic University, Shenzhen 518000, Guangdong Province, China
    3 Anhui Province Industrial Generic Technology Research Center for Alumics Materials, Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, School of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000, Anhui Province, China
  • Received:2024-05-07 Revised:2024-05-27 Accepted:2024-05-28 Published:2024-06-04
  • Contact: Email: wangzl@chnu.edu.cn (Zhongliao Wang)
  • Supported by:
    the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(HZQB-KCZYB-2020083); Shenzhen Science and Technology Program(KCXFZ20211020163816023); Shenzhen Zhongdi Construction Engineering Co., Ltd. cooperation project(22100245); Key Research Project in Natural Sciences for Higher Education Institutions by the Ministry of Education(2022AH050396)

Abstract:

Photocatalytic water splitting (PWS) provides an optimal approach for the sustainable production of green hydrogen. NH2-modified covalent triazine frameworks (CTFs-NH2) hold potential in PWS due to robust light uptake, optimal charge separation, and considerable redox potential. However, the high surface reaction barriers hinder the efficiency of PWS owing to the conversion difficulty of intermediate products. Modulating the Lewis basicity of NH2 on CTFs offers a feasible route for addressing this challenge. In this work, electron-donating ethyl (C2H5) and electron-withdrawing 5-fluoroethyl groups (C2F5) are introduced at the para position of amine groups, producing C2H5-CTF-NH2 and C2F5-CTF-NH2, to adjust the Lewis basicity of CTF-NH2. Through DFT calculations, the optical properties, excited states, electronic structures, dipole moments, and surface reaction processes of the CTF-NH2, C2H5-CTF-NH2 and C2F5-CTF-NH2 are simulated. The results indicate that the electron-withdrawing C2F5 group can decrease the electron density and Lewis basicity on NH2, thereby lowering the energy barriers for hydrogen and oxygen evolution reactions, effectively ameliorating the PWS efficiency of CTF-NH2. This work unveils an innovative approach for donor-acceptor-regulated CTFs for the application of PWS.

Key words: Donor, Acceptor, Water splitting, CTFs, Lewis basicity