Effect of the surfactant nature on the thermo-stability of surface modified SnO 2 nanoparticles

Abstract

The modification of particle surface properties by the addition of small surfactant molecules in the initial sol is one strategy to minimize the strong tendency to aggregation and coarsening of nanoparticles prepared from the sol–gel process. In this work, the effect of the nature of the surfactant, Tiron ® ((OH) 2C 6H 2(SO 3Na) 2 · H 2O, anionic) or Catechol ® (C 6H 4-1,2-(OH) 2, non-ionic) or Maptac ® ([N(CH 3) 3(CH 2) 3NHCOC(CH 2CH 3)] +Cl −, cationic), grafted on the SnO 2 nanoparticles on the mesoporosity of powders fired at 600 °C is presented. SnO 2 powders were prepared from an one-pot sol–gel route in which the hydrolysis of SnCl 4 · 5H 2O in aqueous solution was carried out in presence of the surfactant. The Fourier transform infrared (FTIR) spectroscopy and gravimetric and differential thermo-analysis (TG/DTA) results show that the thermo-stability of surface grafted SnO 2 nanoparticles obeys the following series: Tiron ® > Catechol ® > Maptac ®. The N 2 adsorption isotherms results evidence that the mesopores texture (specific surface area, pore volume and average pore size) can be tuned in a controlled way by increasing the amounts of Tiron ® or Catechol ® molecules grafted on the surface of SnO 2 nanoparticles.