2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 47Citation - Scopus: 53Synthesis of Α-fe2o3< Heterogeneous Composites by the Sol-Gel Process and Their Photocatalytic Activity(Elsevier Science Sa, 2020) Bouziani, Asmae; Park, Jongee; Ozturk, Abdullahalpha-Fe2O3/TiO2 heterogeneous composites were synthesized by the sol-gel process to increase the photocatalytic activity of TiO2. The structural, morphological, and optical characteristics of the composites were determined by X-ray diffraction, scanning electron microscope, and UV-vis diffuse reflectance spectroscopy. Results revealed that the incorporation of alpha-Fe2O3 to TiO2 widened the visible light absorption ability of TiO2. It was realized that the calcination temperature plays a crucial role in morphology development hence photocatalytic activity of the alpha-Fe2O3/TiO2 heterogeneous composites. The photocatalytic activity of the composites calcined at various temperatures was evaluated for the degradation of Methylene Blue (MB) and Phenol (Ph) in aqueous medium under UV and sun-like illuminations. The alpha-Fe2O3-TiO2 composites exhibits superior photocatalytic efficiency to degrade both MB and Ph as compared to both pristine TiO2 and pristine alpha-Fe2O3 under sun-like illumination. The alpha-Fe2O3/TiO2 composite degraded approximately 90 % of MB and 50 % of Ph in 180 min sun-like illumination. Improvement in photocatalytic activity is attributed to the separation of photogenerated electron/hole pairs through the interaction of alpha-Fe(2)O(3 )and TiO2.Article Citation - WoS: 5Citation - Scopus: 6Microporous vanadosilicate films with tailorable V4+/V5+ratio to achieve enhanced visible-light photocatalysis(Elsevier, 2021) Kuzyaka, Duygu; Uzun, Ceren; Yildiz, Ilker; Kaya, Murat; Akata, BurcuThis study investigates the changes induced into the photocatalytic activity under solar light irradiation upon changing the structural film properties and tailor the concentration of defects in microporous vanadosilicate AM6 films. For this purpose, the preparation of AM-6 films with different V4+/V5+ ratios and their utilization as photocatalysts for the decomposition of MB were carried out. Two approaches were used for obtaining AM-6 films with different V4+/V5+ ratios: altering the seed layer coating technique and altering the molar water content of the secondary growth gel. It was seen that dip coating method resulted in an increase in the thickness of the films and it was presumed that the adsorption of MB by AM-6 films was the predominant factor in photocatalytic activity. The second approach of increasing the molar water content of the secondary growth gel provided an increase in the defect concentration resulting in an enhanced photocatalytic activity under the solar light. In the current study, the defect concentration of the prepared films was determined by using XPS and Raman spectroscopy techniques. Accordingly, it was determined that the samples with lower amount V4+/V5+ ratio showed better photocatalytic activity under the solar light irradiation indicating that V5+ cations are responsible for the photocatalytic activity under visible light irradiation. This work provides methods of production of microporous films showing photocatalytic activity under visible light without the requirement of any post-synthesis treatments.
