TiO2 nanotube arrays sensitized by copper (II) porphyrins with efficient interfacial charge transfer for the photocatalytic degradation of 4-nitrophenol

Xian-Tai Zhou; Xiao-Hui Liu; Xing-Jiao Huang; Hong-Bing Ji

doi:10.1016/j.jhazmat.2021.126869

TiO₂ nanotube arrays sensitized by copper (II) porphyrins with efficient interfacial charge transfer for the photocatalytic degradation of 4-nitrophenol

J Hazard Mater. 2022 Jan 15:422:126869. doi: 10.1016/j.jhazmat.2021.126869. Epub 2021 Aug 10.

Authors

Xian-Tai Zhou¹, Xiao-Hui Liu¹, Xing-Jiao Huang², Hong-Bing Ji³

Affiliations

¹ Fine Chemical Industry Research Institute, School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, PR China.
² Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, PR China.
³ Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, PR China; School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, PR China. Electronic address: jihb@mail.sysu.edu.cn.

PMID: 34399216
DOI: 10.1016/j.jhazmat.2021.126869

Abstract

In this paper, photocatalysts based on TiO₂ nanotubes (TNTs) and TiO₂ nanotube arrays (TNTAs) sensitized by Cu(II) meso-tetrakis(N-ethylpyridinium-4-yl) porphyrin (CuTEPyP) were synthesized and their structures were characterized by various analytical methods. The photocatalytic activities of both composites were then investigated through degradation of 4-nitrophenol (4-NP) in aqueous solutions under visible light irradiation. It was found that CuTEPyP/TNTAs could eliminate 95% 4-NP within 4 h, which was considerably higher than the yield obtained with CuTEPyP/TNTs (56%) under the same conditions. Compared to CuTEPyP/TNTs, the improved photocatalytic activity of CuTEPyP/TNTAs can be ascribed to increased light absorption, high separation rate of photo-generated charge pairs, and efficient charge transfer. A plausible photocatalytic degradation mechanism involving hydroxyl radicals, superoxide radical anions and singlet oxygen species was also proposed. This work presents an efficient paradigm for eliminating 4-NP under visible light irradiation.

Keywords: Charge transfer; Photocatalytic degradation; Porphyrin; TiO(2) nanotube arrays; Visible light.