Physicochemical characteristics and photocatalytic performance of Tin oxide/montmorillonite nanocomposites at various Sn/montmorillonite molar to mass ratios

Abstract Nanocomposites of tin oxide immobilized in montmorillonite (Mt) with various Sn/Mt. mole-to-mass ratios were prepared for photocatalysis application. The prepared samples were characterized by x-ray diffraction, transmission electron microscopy, N2 adsorption–desorption analysis, and diffuse reflectance UV–visible spectroscopy. The relationships between the physicochemical characteristics and photocatalytic activities of the materials were evaluated in terms of rhodamine B photocatalytic degradation. From the results, the samples showed that the Sn/ Mt. mole-to-mass ratio affects the increase in the interlayer space of the montmorillonite structure, and the particle size of the dispersed SnO2 nanoparticles increases with increasing ratio, ranging from 10 to 50 nm. The BET specific surface area, pore volume, and band gap energy of the nanocomposites are related with the structural changes, which are closely related with the SnO2 content. The materials exhibit excellent photocatalytic activity as indicated by their higher turnover number and degradation efficiency than those of SnO2 and related photocatalysts. Statistical optimization of the effect of the physicochemical characteristics of the photocatalyst on photocatalytic activity by using the logit model revealed that SnO2 and pH affect the degradation efficiency and initial rate of rhodamine B degradation.