J. Mater. Sci. Technol. ›› 2024, Vol. 182: 67-78.DOI: 10.1016/j.jmst.2023.09.038

• Research Article • Previous Articles     Next Articles

Metal-organic framework [NH2-MIL-53(Al)] functionalized TiO2 nanotube photoanodes for highly stable and efficient photoelectrochemical cathodic protection of nickel-coated Mg alloy

Huan Yaoa, Ruifeng Zhangb, Yu Wena, Yue Liua, Gang Yuc, Zhi-Hui Xiea,*   

  1. aChemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, China;
    bSchool of Materials Science and Engineering, Central South University, Changsha 410083, China;
    cState Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
  • Received:2023-07-10 Revised:2023-08-30 Accepted:2023-09-13 Published:2024-05-20 Online:2024-05-15
  • Contact: *E-mail address: zhxie@cwnu.edu.cn (Z.-H. Xie)

Abstract: Metal-organic framework [MOF, i.e., NH2-MIL-53(Al)] modified TiO2 (NMT) composite photoanodes were successfully prepared by hydrothermal synthesis and were used for the photoelectrochemical cathodic protection (PECCP) of nickel-plated magnesium alloy (Mg/Ni). Results showed that the synthesis temperature significantly impacted the morphology and PECCP performance of the NMT photoanodes. The NMT@150 photoanode prepared at a reaction temperature of 150 °C exhibited the best PECCP performance and produced a current density of 1980 μA cm-2 under visible light irradiation, which was 19.8 times higher than that of a single TiO2 photoanode. The composite photoanode could polarize the open circuit potential of the coupled Mg/Ni electrode to -876 mV and remain relatively stable within 35 h. XPS and EPR tests showed that a Z-scheme heterojunction was formed between the NH2-MIL-53(Al) and TiO2 nanotubes, allowing the photogenerated electrons to accumulate mainly on the conduction band of NH2-MIL-53(Al). The heterojunction greatly promoted the separation and transfer of photogenerated electron-hole in the NMT composite photoanode, significantly enhancing the PECCP performance for Mg/Ni.

Key words: Magnesium alloy, Corrosion, Nickel coating, Electroless, Photoelectrochemical cathodic protection