Synthesis and characterization of α-Ag2MoO4/β-Ag2MoO4 heterostructure obtained by fast and simple ultrasonic spray pyrolysis method at different temperatures

In this work, microspheres of α-Ag 2 MoO 4 /β-Ag 2 MoO 4 were obtained by ultrasonic spray pyrolysis (USP) at temperatures of 400, 500, 600, and 700 °C. Characterizations of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), Raman scattering, and ultraviolet–visible spectroscopy (UV–Vis) were performed on the samples. The beta phase is present in all samples, while the alpha phase forming α/β-Ag 2 MoO 4 appears from 500 to 700 °C. FE-SEM images indicate the tendency of micrometric sphere formation, in which the increase of temperature promotes a smoothing on the surface. The α/β-Ag 2 MoO 4 heterostructure was a better photocatalytic performance on methylene blue dye (MB) degradation than the pure beta phase. The MB was 87% reduced by the pure beta phase and 100% reduced by the α/β-Ag 2 MoO 4 after 45 min of photocatalysis.