Photocatalytic and sensing properties in propane atmospheres of MgSb₂O₆ nanoparticles synthesized by a chemical method

MgSb₂O₆ nanoparticles with a trirutile-type structure were synthesized using a chemical process assisted by microwave radiation to investigate their photocatalytic activity in discoloring an aqueous solution of malachite green (MG) and their application as a gas sensor in propane atmospheres (C₃H₈). The crystallinity of the calcined oxide at 700 °C was analyzed by X-ray diffraction. The material’s microstructure was studied via scanning electron microscopy (SEM), revealing irregular particles ranging from 20 to 180 nm and microplates with dimensions of ~301 height and ~115 nm. Transmission electron microscopy (TEM) analysis yielded an average nanoparticle size of approximately ~19.32 nm. The optical properties of the oxide, analyzed using UV–Vis spectroscopy, indicated a band gap of 3.85 eV. Detection properties of MgSb₂O₆ thick films in dynamic air (1500 cm³/min) and propane atmospheres (560 ppm) were measured under direct current (D.C.) conditions with applied voltages ranging from 7 to 25 V at a constant temperature of 400 °C. The sensor’s response and recovery times were estimated in the order of seconds. Photocatalytic activity was evaluated by monitoring the photo-discoloration of malachite green at a concentration of 5 ppm. The results showed that the MgSb₂O₆ is a potential candidate for photocatalytic applications since it achieves a discoloration of 50% in 210 min of exposure to ultraviolet light (254 nm), despite using a small quantity of MgSb₂O₆.