Synthesis of CaMoO4/g-C3N4 Heterojunctions and Evaluation of their Photocatalytic Properties for Dye Degradation
Carbon Nitride, Calcium Molybdate, Heterojunction, Methylene Blue, Crystal Violet.
The development of efficient photocatalysts for environmental depollution caused by textile dyes remains a challenge to be solved. In this sense, the combination of two materials forming composites in order to improve the characteristics of both, and its photocatalytic application appears as something promising. In this work, the microwave-assisted hydrothermal synthesis of II-type CaMoO4/g-C3N4 (CMO/CN) heterojunctions is reported, varying the synthesis time (between 15 and 60 minutes) and the molar percentage of g-C3N4 (between 40 and 70%). The samples were characterized by the techniques of X-Ray Diffraction, Diffuse Reflectance Spectroscopy in the UV-Visible region, Raman Spectroscopy, Photoluminescence, Field Emission Scanning Electron Microscopy, X-Ray Photoelectron Spectroscopy, Nitrogen Adsorption-Desorption Isotherms and Resonance Spectroscopy Electronic Paramagnetics. The photocatalytic activity of CaMoO4/g-C3N4 composites was evaluated in the degradation of methylene blue and crystal violet dyes under ultraviolet light irradiation. The heterojunction with 70% CN obtained better results than the other samples, reaching 99% degradation of methylene blue in 120 minutes and more than 95% degradation of crystal violet after 180 minutes. Furthermore, reuse tests aiming at photocatalytic stability, scavenger tests in order to observe the active radicals and tests under simulated visible light irradiation and sunlight in order to analyze the influence of the light source on the degradation efficiency were carried out.