MoO3 is an n-type semiconductor with unique properties such as photocatalytic efficiency and different morphologies, thus attracting considerable attention and being studied both alone and in association with other semiconductors with the aim of further improving its properties. In this work, obtaining the compound α-MoO3/Ag/C₃N₄ will be discussed. The research is divided into four stages in which the spray pyrolysis method was initially optimized to obtain the α-MoO₃ phase. Spray pyrolysis syntheses were performed at different precursor concentrations (0.1M, 0.15M, 0.2M and 0.3M), temperatures (600 °C to 1000 °C), flow rates (1 L/min to 5 L/min) and powers (60%, 70% and 100%). The second stage, in turn, addressed the analysis of the influence of the ultrasonic tip on the morphology and final properties of the material. The materials were characterized by the techniques of X-Ray Diffraction (DRX), Spectroscopy in the UV-Visible region (Uv-Vis), Scanning Electron Microscopy by Field Emission (MEV-FEG), Photoluminescence and evaluated their photocatalytic efficiency against to organic dyes. The diffractogram showed the attainment of the α-MoO3 orthorhombic phase with a space group of 62 Pbnm as well as the presence of the hydrated phase in the analyzed samples. The analyzed samples showed gap energy values ranging from 3.41 eV to 3.86 eV. Gap energy values higher than those found in the literature were observed in samples MO 9, P 5, P 10 and P 15. According to the photocatalytic analysis, sample MO 12 shows complete degradation of methylene blue after about 50 minutes and presents photoluminescence emission in violet, blue and green. Through the micrographs, it was possible to observe the influence of the synthesis parameters and the ultrasonic process itself on the morphology of the samples, variations that influenced the photocatalytic activity and photoluminescence of the samples.