Surface Decomposition of Dimethyl Methylphosphonate on SnO 2 Nanoparticles: Role of Nanoparticle Size

We report the effect of SnO₂ particle size on the adsorption behaviour of dimethyl methylphosphonate (DMMP). SnO₂ nanoparticles with different particle sizes have been successfully synthesised by the reverse microemulsion method. Transmission electron microscopy and X-ray diffraction results were used to evaluate size distribution, shape and structure of the prepared SnO₂ nanoparticles. The infrared spectra of adsorbed DMMP on SnO₂ show that the adsorption is dissociative. In addition, it is shown that the size of SnO₂ nanoparticles does not affect the reaction mechanism. Adsorption isotherms of DMMP show that by decreasing the size of SnO₂ nanoparticles, the amount of DMMP adsorbed is increased. In addition, the calculated heats of adsorption of DMMP are increased as the SnO₂ nanoparticle size decreases.