Influence of the Microwaves on the Sol-Gel Syntheses and on the Properties of the Resulting Oxide Nanostructures

Abstract

Among the chemical methods in the liquid phase, the sol–gel technique is a versatile and efficient method for pure or doped metal oxide films or powders preparation, showing some advantages over other preparation techniques (high homogeneity, the possibility to introducing dopants in large amount, low processing temperature and control over the stoichiometry). Combining the sol–gel (SG)method with the effect of ultrasounds(US) or microwaves (MW) leads to improving the sol–gel procedure. The microwave-assisted sol–gel method is most frequently used for obtaining nanocrystalline, monodispersed oxide nanoparticles, or to transform amorphous gels into well-crystallized nanopowders. Less studied is the influence of the microwaves on the sol–gel reactions in solutions. The benefit of using microwave-assisted sol–gel preparation highly depends on the reagents used and on the composition of the studied systems. In the present chapter, results on the influence of the microwaves on the chemical reactions that take place during the sol–gel synthesis and on the properties of the resulted samples are discussed.

Effect of Thermal Treatment on the Structure and Morphology of Vanadium Doped ZnO Nanostructures Obtained by Microwave Assisted Sol–Gel Method

“…Increased attention has recently been paid to the synthesis of functional nanomaterials using microwave energy [ 10 , 11 ]. When compared to traditional heating methods, the microwave (MW) assisted sol–gel technology is stated to be a faster, easier, cheaper, more energy-efficient, and effective process [ 12 , 13 , 14 ]. The employment of microwaves is suitable for the technological field since it decreases the reaction time from days or hours to minutes, improves the properties of synthesized nanostructures, and facilitates the formation of oxide nanocrystalline films on various substrates [ 3 , 15 , 16 ].…”