Preparation and characterization of silver thiocyanate – tetrabromo-tetrachlorofluorescein inclusion material and its adsorption to synthetic dye

From the adsorptive precipitation of SCN−, tetrachloro-tetrabromofluorescein (TBTCF) and Ag+, we found in-situ embedment of TBTCF into growing silver thiocyanate particles to form ternary electronegative inclusion material. The composition, size and phase of the material were determined by spectrophotometry and ICP and characterized by XRD, SEM, etc. The results showed that in-situ inclusion particles {[Ag(SCN)]m(TBTCF)}n2n− (m = 33 ± 11) were formed. The inclusion particles adsorbed cationic dyes selectively and rapidly. A representative cationic dye, ethyl violet (EV), was used to investigate the performance of the ternary inclusion particles and the mechanism involved. The equilibrium adsorption capacity of the Ag(SCN)/TBTCF inclusion particles is 202 mg/g EV, over 14 times higher than absorption to the silver thiocyanate–only particles and slightly more than activated carbon. Moreover, the adsorption approached the equilibrium in 10 min, which is much less than that with activated carbon in about 2 h. In this work, a simple preparation method of the inclusion material as dye adsorbent was established and it will play an important role in the removal or recovery of cationic organic substances from aqueous.