Now showing 1 - 2 of 2
  • Publication
    The role of Nitrogen-Doped TiO2 supported by platinum catalyst synthesized via various mode preparations for photocatalytic nnhancement
    ( 2022-11-01)
    Natar N.S.
    ;
    Ghani N.I.A.
    ;
    Hamzah S.R.
    ;
    Rosli M.A.
    ;
    Muhamad N.A.
    ;
    Azami M.S.
    ;
    Ishak M.A.M.
    ;
    ;
    Nawawi W.I.
    The limitations of TiO2 as a photocatalyst such as the larger bandgap energy, which only activates under the UV region, give a lower photocatalytic activity. This study reports the role of the N and Pt co-dopant on the modification of the TiO2 photocatalyst for photocatalytic degradation of methylene blue dye under different mode preparations, i.e., sequential and vice-versa modes. The sequential mode preparation of the N and Pt co-dopant TiO2 photocatalyst consisted of the initial preparation of the N-doped TiO2 (N-TiO2) under the calcination method, which was then further doped with platinum (Pt) through the photodeposition process labeled as NPseq-TiO2, while the vice-versa mode was labeled as PNrev-TiO2. About 1.58 wt.% of N element was found in the NPseq-TiO2 photocatalyst, while there was no presence of N element detected in PNrev-TiO2, confirmed through an elemental analyzer (CHNS-O) and (EDX) analysis. The optimum weight percentage of Pt for both modes was detected at about ±2.0 wt.%, which was confirmed by inductively coupled plasma-emission spectroscopy (ICP-OES). The photoactivity under methylene blue (MB) dye degradation of the NPseq-TiO2 photocatalyst was 2 and 1.5 times faster compared to the unmodified TiO2 and PNrev-TiO2, where the photodegradation rates were, ca., 0.065 min−1 and 0.078 min−1, respectively. This was due to the N elements being incorporated with the TiO2 lattice, which was proven by UV-Vis/DRS where the bandgap energy of NPseq-TiO2 was reduced from 3.2 eV to 2.9 eV. In addition, the N generated a stronger PL signal due to the formation of oxygen vacancies defects on the surface of the NPseq-TiO2 photocatalyst. The higher specific surface area as well as higher pore volume for the NPseq-TiO2 photocatalyst enhanced its photocatalytic activity. Moreover, the NPseq-TiO2 showed the lowest COD value, and it was completely mineralized after 7 h of light irradiation. The preparation order did not affect the Pt dopant but did for the N element. Therefore, it is significant to investigate different mode preparations of the N and Pt co-dopant for the modification of TiO2 to produce a good-quality photocatalyst for photocatalytic study under the photodegradation of MB dye.
      1  9
  • Publication
    Effect of Photoetching Process onto Immobilized PANI/TiO2Films towards Photocatalytic Degradation of RR2 dye
    ( 2020-11-24) ; ;
    Nawawi W.I.
    ;
    Natar N.
    Polyaniline (PANI) and P-25 Titanium dioxide (TiO2) was fabricated as immobilized P-25TiO2/PANI/ENR/PVC film and reported on the photocatalytic study. PANI and TiO2 was immersed into the organic solvent and being coated onto glass plates under influenced of ENR/PVC polymeric binder by using a dip-coating method. It was found that, the removal of RR2 dye nearly good as suspension system after the pre-irradiation process. Based on COD and BET results, it showed that the optimum time of etching process was 7 hours irradiation time. This pre-irradiation process enhanced the removal of dye due to leached out of excessive binder and also exhibit visible light active after insertion of PANI into the immobilized system.
      17  2