Decolorization of Methylene Blue by Ag/SrSnO₃ Composites under Ultraviolet Radiation

Abstract

SrSn(OH)6 precursors synthesized by a cyclic microwave radiation (CMR) process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG) were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), Fourier transform infrared (FTIR) spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl) dye under ultraviolet (UV) radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.

Supporting the photocatalysts on ZrO2: An effective way to enhance the photocatalytic activity of SrSnO3

“…At pH 3.5, a meaningful increase in the decolorization percentage was observed after Ag + addition into the solution. The increase of the photocatalytic activity may be assigned to the deposition of Ag on the catalyst surface after Ag + reduction, improving the electron capture by O2, as already reported by Junploy et al [66]. At the end of the photocatalytic test, stabilization of the decolorization occurs, which may be related to the formation of metallic silver in suspension that avoids light absorption by the catalyst affecting its efficiency [67].…”

SYNTHESIS AND CHARACTERIZATION OF SrSnO3 USING DIFFERENT SYNTHESIS METHODS

“…Finally, SSR has the highest peaks for Sr 3d 5/2 and Sr 3d 3/2 at 130.8 and 132.5 eV, respectively. According to these results, all have 2 peaks within 130 -134 eV binding energy values, which corresponds to Sr 2+ [15]. However, the variance in each spectrum of the three methods may suggest that the quality of Sr 2+ bonding with main lattice is different, with SSR having the highest peak followed by sol-gel and hydrothermal.…”

“…Since the SSR method did not involve additional solutions or hydrates, there are no shoulders or peaks indicating that hydrated oxide species were present [8]. [15]. The peaks are highest for SSR followed by hydrothermal and sol-gel.…”