Photodeposition mediated synthesis of silver-doped indium oxide nanoparticles for improved photocatalytic and anticancer performance

Indium oxide nanoparticles (In₂O₃ NPs) are being investigated for a number of applications including gas-sensing, environmental remediation, and biomedicine. We aimed to examine the effect of silver (Ag) doping on photocatalytic and anticancer activity of In₂O₃ NPs. The Ag-doped (2%, 4%, and 6%weight) In₂O₃ NPs were synthesized by the photodeposition method. Prepared samples were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), UV-Vis spectroscopy, and the photoluminescence (PL). XRD data showed that Ag-doping increases the crystallinity of In₂O₃ NPs. SEM and TEM images indicated that In₂O₃ NPs have spherical morphology with smooth surfaces, and Ag-doping increases the size without affecting the particle's shape. XPS spectra showed the oxidation state and the presence of Ag in In₂O₃ NPs. Band gap energy of In₂O₃ NPs decreases with increasing the concentration of Ag (3.41 eV to 3.12 eV). The peak intensity of PL spectra of In₂O₃ NPs also reduces with the increment of Ag ions suggesting the hindrance of the recombination rate of e^-/h⁺. The photocatalytic activity was measured by the degradation of Rh B dye under UV irradiation. The degradation efficiency of Ag-doped (6%) In₂O₃ NPs was 92%. Biochemical data indicated that Ag-doping enhances the anticancer performance of In₂O₃ NPs against human lung cancer cells (A549). Moreover, Ag-doped In₂O₃ NPs displayed excellent biocompatibility in normal human lung fibroblasts (IMR90). Overall, this study demonstrated that Ag-doping enhances the photocatalytic activity and anticancer efficacy of In₂O₃ NPs. This study warrants further investigation on the environmental and biomedical applications of Ag-In₂O₃ NPs.

A Review on Synthesis and Characterization of Ag2O Nanoparticles for Photocatalytic Applications

Even though the photocatalytic processes are a good technology for treatment of toxic organic pollutants, the majority of current photocatalysts cannot utilize sunlight sufficiently to realize the decomposition of these organic pollutants. As stated by various researchers, metal oxide nanoparticles have a significant photocatalytic performance under visible light source. Among various chemical and physical methods used to synthesize nanostructured silver oxide, green synthetic route is a cheaper and environmental friendly method. To confirm the optimum production of Ag2O NPs, effect of pH, extract concentration, metal ion concentration, and contact time were optimized. The structure, morphology, crystallinity, size, purity, elemental composition, and optical properties of obtained Ag2O NPs were characterized by different techniques, such as scanning electron microscopy (SEM), transmission electron microscope (HRTEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and UV-visible spectrophotometer accordingly as revealed by our literature review. The photocatalytic performance of the synthesized nanocrystalline Ag2O by photocatalytic degradation of organic dyes under visible light irradiation has been discussed thoroughly in this review. Many past studies revealed that organic dyes and pollutants are decomposed completely by green synthesized Ag2O NPs under irradiation of visible light.

Synthesis, Characterization and Photocatalytic Activity of N-doped Cu2O/ZnO Nanocomposite on Degradation of Methyl Red

In this study, a N-doped Cu2O/ZnO nanocomposite was prepared by a co-precipitation and thermal decomposition technique from CuCl2, 2H2O, ZnSO4, 7H2O and CO(NH2)2 as precursors. The as-synthesized nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared analysis (FT–IR) and an ultraviolet–visible (UV–Vis) reflectance spectrometer. From the XRD diffractogram of N-doped Cu2O/ZnO nanocomposite, cubic and hexagonal wurtzite crystal structures of Cu2O, and ZnO, respectively were identified. The UV-vis reflectance spectra illustrated that the absorption edge of N-doped Cu2O/ZnO nanocomposite is more extended to the longer wavelength than ZnO, Cu2O and Cu2O/ZnO nanomaterials. FT–IR bands confirmed the presence of ZnO, Cu2O, and nitrogen in the N-doped Cu2O/ZnO nanocomposite. Photocatalytic activity of the as-synthesized nanocomposite was tested for methyl red degradation using sunlight as an energy source by optimizing the concentration of the dye and amount of the catalyst loaded. The degradation efficiency was greater in N-doped Cu2O/ZnO nanocomposite as compared to ZnO, Cu2O and Cu2O/ZnO nanomaterials. This is due to the coupling of the semiconductors which increases the absorption and exploitation capability of solar light and increases the charge separation as well. Besides that, nitrogen doping can extend absorption of light to the visible region by decreasing the energy gap. Therefore, N-doped Cu2O/ZnO nanocomposite is a solar light-active photocatalyst which can be used in the degradation of organic pollutants.