Silica-titania hybrid nanoparticles for the extraction of zinc ions from water samples

Abstract

This study prepares and evaluates the performance of the hybrid nanoparticles as absorbent to extract selected heavy metal ion namely zinc from water samples. SiO2–TiO2 hybrid nanoparticles was prepared using sol-gel method which used the combination of titania and silica sols. Titania sol was prepared at a molar ratio of 1 TiCl3: 3 NaOH, while silica sol was prepared at molar composition of 1 TEOS: 2 H2O: 2 C2H5OH: 0.5 HCl. The prepared solid was characterized using XRD, FTIR, nitrogen adsorption analysis and SEM. XRD results showed that the sample is amorphous due to the presence of silica in the sample. Low-intensity peaks of are observed at 2θ 28.302º, 41.887º, and 68.585º indicating the presence of titania as minor component. Nitrogen adsorption analysis revealed that SiO2-TiO2 hybrid nanoparticles have mesoporous structure with type IV isotherm and average pore sizes of 12.45 nm. The BET surface area of SiO2-TiO2 hybrid nanoparticles is 129.326 m2/g and t-Plot has proved that SiO2-TiO2 hybrid nanoparticles only composed of mesopores. Several extraction conditions were optimized namely pH level, shaking time and mass of adsorbent. The SiO2-TiO2 hybrid nanoparticles adsorbent has demonstrated to be potentially applicable for the removal of zinc ion from water samples.