3.2 Iodine adsorption experiments
The iodine adsorption curve of shaped silicalite-1 at 348 K is shown in Figure 3. At first 15 hours of the adsorption experiment, the amount of adsorption on shaped silicalite-1 was proportional to the adsorption time. After that, the adsorption speed slowed down, finally reached the adsorption platform after about 23 h. After the adsorption completed, the color of shaped silicalite-1 changed from white to red-brown, as shown in Figure 4. The saturated adsorption capacity for shaped silicalite-1 was 507 mg g-1, between those of power silicalite-1 and hydrophobicity-intensified silicalite-130, manifesting the molding process of shaped silicalite-1 was successful. In addition, this iodine adsorption capacity was also higher than other inorganic adsorbents reported previously, demonstrating huge application potential in iodine adsorption. The results of iodine adsorption capacity in previous studies and this work are shown in Table 1.
Figure 3 Iodine uptake curves for silicalite-1 at 348 K