Acta Physico-Chimica Sinica ›› 2019, Vol. 35 ›› Issue (11): 1232-1240.doi: 10.3866/PKU.WHXB201901025

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Fabrication of a ZnSe/MoO3/TiO2 Composite Film Exhibiting Photocathodic Protection Effect

Haipeng WANG1,Zichao GUAN1,Xia WANG1,Piao JIN1,Hui XU1,Lifang CHEN1,Guangling SONG2,*(),Ronggui DU1,*()   

  1. 1 Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
    2 Center for Marine Materials Corrosion and Protection, College of Materials, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2019-01-09 Accepted:2019-02-26 Published:2019-03-14
  • Contact: Guangling SONG,Ronggui DU E-mail:guangling.song@hotmail.com;rgdu@xmu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21573182);the National Natural Science Foundation of China(51731008);the National Natural Science Foundation of China(51671163);the National Natural Science Foundation of China(21621091);the National Natural Science Foundation of China(J1310024)

Abstract:

TiO2 is a semiconductor material with excellent photoelectrochemical properties that can provide photocathodic protection for metals. However, TiO2 can only absorb ultraviolet (UV) light at wavelengths of < 380 nm because of its wide band gap. In addition, photo-induced electron-hole pairs in the TiO2 semiconductor easily recombine, which leads to a low photoelectric conversion efficiency. Another shortcoming is that pure TiO2 semiconductors cannot sustain photocathodic protection in the dark, which may limit their practical applications to provide photocathodic protection. To address these shortcomings, various modification methods have been established by preparing TiO2 composite materials to improve their photoelectrochemical properties. In this study, a ZnSe- and MoO3-modified TiO2 nanotube composite film with charge storage ability was prepared to enhance its photocathodic protection effect on stainless steel. A TiO2 nanotube array film was prepared on a Ti foil via anodic oxidation and then MoO3 and ZnSe particles were deposited onto the film by cyclic voltammetry and pulse electrodeposition, respectively, to afford a ZnSe/MoO3/TiO2 nanotube composite film having a cascade band structure. Scanning electron microscopy observations showed that the TiO2 film consisted of ordered nanotubes with an average inner diameter of approximately 100 nm and wall thickness of approximately 15 nm. This nanotube structure remained intact after MoO3 and ZnSe particle deposition on the film. Energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses indicated that the prepared nanotube composite film was composed of ZnSe, MoO3, and TiO2. The UV-Vis absorption and photoluminescence spectra showed that the photoresponse of the composite film was extended to the visible light region and the photo-induced electron-hole pair recombination was reduced. Photoelectrochemical and electrochemical measurements indicated that the photocurrent intensity of the composite film in a 0.5 mol·L−1 KOH solution was two-fold higher than that of the pure TiO2 film. Under white light illumination, the ZnSe/MoO3/TiO2 composite film decreased the potential of the coupled 403 stainless steel (403SS) in a 0.5 mol·L−1 NaCl solution by 470 mV (relative to the corrosion potential), demonstrating an effective photocathodic protection effect. It should be noted that the composite film exhibited a charge storage capability and could continuously provide cathodic protection for 22.5 h after illumination was stopped. In addition, electrochemical impedance spectroscopy results indicated that the composite film significantly decreased the charge transfer resistance of the coupled 403SS, highlighting the photocathodic protection effect on 430SS.

Key words: Anodic oxidation, Electrochemical deposition, TiO2 nanotube, Stainless steel, Photoelectrochemical property, Photocathodic protection

MSC2000: 

  • O646