Hydrothermal Method for Synthesis of Materials

Abstract

Hydrothermal method of synthesis has emerged as the primary choice for synthesizing several strategic materials. The application of this method has diversified in the last few decades into several advanced fields of material science with the progress in the understanding of the process and with the evolution of better instrumentation. The journey of hydrothermal synthesis started with the preparation of minerals particularly quartz crystals using the temperature gradient method with the emphasis on quality of the product in terms of purity, defects, and size. This method gained immense prominence with the emergence of mesoporous zeolites which act as excellent catalyst for the cracking of petroleum. Hydrothermal synthesis is the most suitable route for the preparation of zeolites and other related mesoporous structures with engineered pores. Detailed studies have been carried out to understand the growth mechanism in the quest of designing the framework with required porosity. Hydrothermal synthesis has emerged as the preferred route for the synthesis of metal oxide nanoparticles. Enhanced dehydration and overall kinetics of the process due to increased temperature result in the formation of the desired product. Designing the hydrothermal synthesis process to tailor the morphology of the product at nanoscale has led to the development of several interesting semiconducting nanoparticles and nano-structured arrays. Variations in the technique like using microwave-assisted hydrothermal method or continuous hydrothermal flow synthesis have helped in further improving the quality of product. The above aspects related to the hydrothermal method of synthesis have been described in this chapter.