Highly ordered TiO2 nanotube arrays wrapped with g-C3N4 nanoparticles for efficient charge separation and increased photoelectrocatalytic degradation of phenol

Huan Wang; Yinghua Liang; Li Liu; Jinshan Hu; Wenquan Cui

doi:10.1016/j.jhazmat.2017.10.044

Highly ordered TiO₂ nanotube arrays wrapped with g-C₃N₄ nanoparticles for efficient charge separation and increased photoelectrocatalytic degradation of phenol

J Hazard Mater. 2018 Feb 15:344:369-380. doi: 10.1016/j.jhazmat.2017.10.044. Epub 2017 Oct 24.

Authors

Huan Wang¹, Yinghua Liang², Li Liu³, Jinshan Hu³, Wenquan Cui⁴

Affiliations

¹ School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, PR China.
² School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, PR China; College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, Tangshan, Hebei, 063210, PR China. Electronic address: liangyh@ncst.edu.cn.
³ College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, Tangshan, Hebei, 063210, PR China.
⁴ College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, Tangshan, Hebei, 063210, PR China. Electronic address: wkcui@163.com.

PMID: 29096250
DOI: 10.1016/j.jhazmat.2017.10.044

Abstract

Novel graphitic carbon nitride nanoparticles (NPs)-wrapped TiO₂ nanotube arrays (NTAs) (g-C₃N₄/TiO₂) were fabricated by a two-step method including an electrochemical anodization technique followed by impregnation under vacuum using urea as precursor. The as-prepared photoelectrode exhibited outstanding photoelectric properties and excellent photelectrocatalytic (PEC) performance for the degradation of phenol under stimulated solar light, which was due to the enhanced light absorption property and improved charge separation efficiency. The introduction of g-C₃N₄ NPs strongly decreased the charge transfer resistance and boosted the charge separation efficiency of TiO₂. The optimum ratio of the g-C₃N₄/TiO₂ yielded a pronounced 4.18-fold higher photocurrent density than TiO₂. Besides, the combination of g-C₃N₄ NPs could negatively shift for the flat band potential of TiO₂, resulting in an enhanced reduction property for the photoelectrocatalytic degradation of organic pollutants. The PEC process for the degradation of phenol over g-C₃N₄/TiO₂ was much higher than the sum of photocatalytic (PC) and electrocatalytic (EC) processes indicating that a photoelectric synergy was achieved on the as-prepared photoelectrode and resulting in an improved PEC performance for the composite photoelectrode.

Keywords: Charge separation efficiency; Organic pollutants; Photoelectrocatalysis; TiO(2) nanotube arrays; g-C(3)N(4) nanoparticles.