Enhanced photo-catalytic activity of the composite of TiO2 and conjugated derivative of polyvinyl alcohol immobilized on cordierite under visible light irradiation

A novel visible light active photo-catalyst named CHC/C-PVA/TiO2, the composite of titanium dioxide (TiO2) with conjugated derivative of polyvinyl alcohol (C-PVA) loaded on a cordierite honeycomb ceramic (CHC) substrate, was fabricated by combining the synthesis of TiO2 sol, preparation of C-PVA via thermally treating polyvinyl alcohol, and immobilization of TiO2 sol and C-PVA on CHC. By detecting the change of UV–vis absorption spectra of the model organic pollutant (methyl orange (MO)) in the presence of the composite under visible light irradiation, the photo-catalytic activity was evaluated and the results show that the CHC/C-PVA/TiO2composite has an enhanced photo-catalytic activity when compared to the CHC/TiO2 composite. Besides, the CHC/C-PVA/TiO2 shows a good photo-catalytic stability after the fourth cycles. The structure analyses by scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) show the coexistence of C-PVA and TiO2 on the CHC and the cracks on the surface of CHC/C-PVA/TiO2. Result of ultraviolet-visible diffuse reflection spectroscopy (UV–vis DRS) reveals that the CHC/C-PVA/TiO2 can absorb both ultraviolet and visible light while result of X-ray photoelectron spectroscopy (XPS) indicates the existence of C, O and Ti elements in the CHC/C-PVA/TiO2. The typical structures as well as the optical characteristics of the CHC/C-PVA/TiO2 are responsible for the enhancement in the photo-catalytic activity.

A novel photocatalyst CHC/C-PVA/TiO2 with cordierite as the support and PVA as the precursor of conjugated polymer was prepared and it shows superior photocatalytic activity under visible light.Figure optionsDownload as PowerPoint slide