RESUMO
Herein, we synthesized a CdSe quantum dots (QDs)-decorated ternary metal oxide nanocomposite of ZnO/TiO2/CuO through a simple hydrothermal method. The prepared nanocomposite exhibited monoclinic, hexagonal, and cubic phase structures in XRD (X-ray diffraction) analysis. UV-vis absorbance spectra showed the broad absorption spectrum. SEM (scanning electron microscopy) clearly showed the presence of nanoparticles and confirmed the elements through elemental mapping. TEM (transmission electron microscopy) confirmed the nanostructure of metal oxides decorated with QDs. The average particle size was 45 nm for metal oxides and 7 nm for QDs. XPS (X-ray photoelectron spectroscopy) also confirmed the surface elemental composition. The prepared nanocomposites were introduced as photoanodes in DSSCs (dye-sensitized solar cells) and as photocatalysts for industrial dye solution. Among these samples, CdSe@CuO/TiO2/ZnO showed an improved performance of PCE (photon conversion efficiency) of 3.68% in DSSC and 96% photocatalytic degradation efficiency. It showed a recycling efficiency of â¼92% after 4 cycles against methylene blue (MB) organic dye under visible light irradiation.
RESUMO
A facile and eco-friendly hydrothermal method was used to prepare carbon quantum dots (CQDs) using orange waste peels. The synthesized CQDs were well dispersed and the average diameter was 2.9 ± 0.5 nm. Functional group identification of the CQDs was confirmed by Fourier transform infrared spectrum analysis. Fluorescence properties of the synthesized CQDs exhibited blue emission. The fluorescence quantum yield of the CQDs was around 11.37% at an excitation wavelength of 330 nm. The higher order nonlinear optical properties were examined using a Z-scan technique and a continuous wave laser that was operated at a wavelength of 532 nm. Results demonstrated that the synthesis of CQDs can be considered as promising for optical switching devices, bio-scanning, and bio-imaging for optoelectronic applications.
