RESUMO
In this work, the CeO2@polypyrrole (CeO2@PPy) core-shell nanosphere has been synthesized via an ultra-sonication method using bath type (WUC-D22H, Daihan Scientific, Korea) and they are utilized for the photo-reduction of hazardous Cr6+ to benign Cr3+. The ultrasonic frequency and power were 20â¯kHz and 100â¯W, respectively. The PPy shielded CeO2 in aqueous solution could prevent the dissolution of CeO2 and to improve the photocatalytic ability of CeO2. X-ray diffraction was used to confirm the crystalline structure of as prepared CeO2@PPy core-shell and FT-IR was used to identify the functional groups. The uniform sized core of PPy and shell of CeO2 were observed by transition electron microscopy. The ultrasonic assisted synthesized CeO2@PPy core-shell exhibits a narrow bandgap (UV-DRS) and good reduction efficiency with higher reusability and stability compared to pure CeO2, PPy and mechanical mixing of CeO2@PPy. Moreover, the synergistic effect of CeO2 and PPy core-shell structure facilitate a higher electron transfer rate and prolong lifetime of photogenerated electron-hole pairs which can achieve good reduction rate of 98.6% within 30â¯min. In particular, the pH, catalyst, and Cr6+ concentration effects were optimized in photocatalytic reduction reactions. Meanwhile, this photocatalysis with fast and effective electron transfer mechanism for the Cr6+ reduction was elucidated. This method opens a new window for simple fabrication of conducting polymers-based metal oxide nanocomposite towards wastewater remediation and beyond.
RESUMO
Dye degrading property to exhibit self-cleaning effect in Poly Ethylene Terephthalate (PET) through photocatalytic effect by Metallo porphyrin and TiO2 has been studied in detail. PET has been modified by step wise deposition of anatase TiO2 and Metallo porphyrin (CuTCNPP, NiTCNPP, ZnTCNPP), self-cleaning property of the modified PET has been studied by photo degradation of rhodamine B (RB) by irradiation under visible light and the degrading ability and the efficiency has been monitored using UV-Vis spectral technique by measuring the change in concentration of RB in the PET at different time intervals. Stability of Metallo porphyrin in PET also measured by UV-Vis spectral method. Indicating the porphyrin attached in PET are highly stable after washing the samples with detergent, water even after irradiating under visible light for more than 5 h. The degradation effectiveness found to be in the order of PET/TiO2/ZnTCNPP > PET/TiO2/CuTCNPP > PET/TiO2/NiTCNPP > TiO2 > PET. The modification made in the PET samples were characterized and confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible spectroscopy (UV-Vis), Field emission scanning electron microscope (FESEM) analysis and the prepared Metallo porphyrin has been confirmed through mass analysis.
RESUMO
Hydrophobic nindigo dyes were designed and successfully synthesized from indigo by reacting with substituted anilines in a simple route. Four nindigo dyes were fruitfully analyzed by 1H NMR 13C NMR, electronic and mass spectrometry. Here, we have firstly introduced these nindigo dyes into dyeing area for the dyeing of unmodified polypropylene fiber in aqueous medium. Dyeing experiments has been performed by using didodecyldimethylammonium bromide dispersing agent to make dye-dispersant complex for enhancing the dispersion of dyes. All the dyes were displayed profound blue color hue on polypropylene. The dyeing efficiency and dye fixation order of the nindigo dyes are 3d > 3c ≥ 3b > 3a. Compound 3d having higher the hydrophobic character (logP â 7.04), so greater the dye ability on the polypropylene fiber and exhibiting deep coloration.
