Synthesis of SnO2 nanoparticles through the controlled precipitation route

Abstract

The controlled precipitation method allowed to the synthesis of SnO2 with advantageous specific properties, such as size and shape employing an aqueous SnCl2·2H2O solution as precursor. Through XRD analyses, the optimum pH value of the solution that yielded the desired product was found to be 6.25. After a thermal treatment at 600 °C, the final powder presented an average particle size below 50 nm with a surface area of 19 m2 g-1 and a large reactivity. The evolution of the most important functional groups during the steps involved in this synthesis route is explained in view of the results obtained with FTIR and XRD. A thorough discussion on the different intermediates involved in the whole process is presented on the basis of hydrolysis and condensation reactions. The conclusions are supported with a complete characterization through differential and gravimetric thermal analysis (DTA/TGA), electron microscopies (SEM/TEM) and surface area determinations (BET).