On the other hand, RhB (Wako Pure Chemicals Industries Ltd., Osaka, Japan) was dissolved in water with a concentration of 1200 ppm, separately. After both suspensions were dispersed well, they were mixed with a volume ratio of 1:1 using a vigorous stirrer for 1 min. Then, the sample was immediately measured using spectroscopy (Shimadzu UV–Vis Spectrophotometer, UV-3150). In addition, for the standard comparison, the RhB sample was also dissolved in water with a concentration of 600 ppm. In addition, the duration time for the measurement was no more than 3 min. The measurements were repeated continuously until 100 min and then several hours and days. Thus, the results could be analyzed as function of time. To corroborate the first time adsorption, we also checked the mixture of the initial concentration for several samples, which compared with the RhB solution in the same calculated concentration. To investigate the effect of pores and morphology, different types of particles (different pore size) were used as an adsorbent.