Study On The Adsorption Of Silver On Shaped Activated Carbon

Activated carbon(AC) loaded with silver(AC-Ag) has been widely used in water treatment, air treatment and catalyst. Shaped activated carbon(SAC) loaded with silver(SAC-Ag) may have the same character with AC-Ag and worth for further research.In the first period, we use AgNO3 as an impregnant to fabricate SAC-Ag. Pretreatment method, reacted time and solution concentration are used as tunable parameter to control the size and distribution of silver particle on SAC. The results shows that pretreatment method effecting intensity to the final form of SAC-Ag, reacted time can be used as a useful way to control, solution concentration can accelerate the reaction and whole reaction can be long-drawn.Then, We compare the deference phenomenon of adsorption between SAC, bamboo carbon, granular carbon, graphite, coke and coal ash. We found that electric and porous are necessary for depositing Ag directly on SAC surface. With this understanding, we carry out a hypothetic model for the phenomenon that SAC can deoxidize Ag+. In this model, a concentration cell is formed when SAC is putted in AgNO3 solution, the inside point of SAC acted as cathode of the cell, then electrons can transfer to the surface of SAC to reaction with Ag+ . A great deal of silver nano-particle is producted in this way.In the third period, this paper validate the hypothetic model by compare the deference phenomenon of SAC powder, SAC thin piece, SAC. The differences between the inside and surface of SAC were also analysis by XPS anslysis, all the results accord with hypothetic mechanism. In addition, SAC was used to fabricate dendritic silver powder. SAC also acted as an electrode to fabricate dendritic silver powder. We also get an excellent result in fabricate porous silver nanocube via AgCl templates.Finally, SAC is study in the adsorption of Au and Pt. SAC also can act a very important role in dealing with the water contaminated by other metal ions like Cd2+, Cr2+ and Pt2+.