Enhancement in photocatalytic selectivity of TiO2-based nano-catalyst through molecular imprinting technology

Environ Sci Pollut Res Int. 2023 Dec;30(58):121929-121947. doi: 10.1007/s11356-023-30747-7. Epub 2023 Nov 14.

Abstract

Improvement in the photocatalytic selectivity is imperative for the effective and efficient utilization of catalysts. In this study, a molecularly imprinted polymer-coated iron-doped titanium dioxide (Fe-TiO2@MIP) nanocomposite was successfully synthesized by precipitation polymerization while using RB-19 as a template. The synthesized nanocomposites (Fe-TiO2@MIP and Fe-TiO2@NIP) were characterized by Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-EMMETT-Teller (BET), and UV-visible spectrophotometry. The optimized binding experiments revealed a high imprinting factor of 5.0 for RB-19. The catalytic degradation efficiency and selectivity of Fe-TiO2@MIP enhanced to almost complete degradation of RB-19 from 70% for the parent Fe-TiO2 and 76% for Fe-TiO2@NIP. An outstanding degradation selectivity of RB-19 was achieved compared to other competitive dyes. Finally, the analysis of the non-degraded and degraded RB-19 by ESI-MS revealed the presence of different intermediates that fits well with the proposed degradation mechanism. The study opens new possibilities of selective photo-degradation of targeted contaminants that may ultimately lead to efficient use of photocatalysts.

Keywords: Heterogeneous photocatalysis; Iron-doped titanium oxide; Molecular imprinting; Photo-degradation; Reactive blue 19.

MeSH terms

  • Catalysis
  • Light*
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Molecular Imprinting*
  • Spectroscopy, Fourier Transform Infrared
  • Titanium / chemistry

Substances

  • Titanium