Sakshi Thakur

During the sol-gel method, the reaction between a metal precursor (e.g. metal alkoxide) and carbamide (urea) involves hydrolysis and condensation reactions. The metal precursor reacts with water to form metal hydroxide, while carbamide acts as a complexing agent to control the reaction. This results in the formation of metal oxide nanoparticles. For example, in the case of titanium isopropoxide as the metal precursor, the reaction can be represented as: Ti(OC3H7)4 + 4H2NC(O)NH2 + 6H2O → Ti(OH)4 + 4H2NCONH2 + 4C3H7OH. The carbamide helps in stabilizing and controlling the nanoparticle growth during the sol-gel process.