【作者】 刘文宏；

【导师】 范必威；

【作者基本信息】 成都理工大学 ， 应用化学， 2004， 硕士

【摘要】 载银活性炭在环境水处理和催化领域都具有重要的研究和应用价值。本文对银在活性炭表面的吸附和分布进行了研究。 离子强度对银离子在活性炭表面的吸附无明显影响；两种性质不同的配位体（氨水和硫代硫酸钠）对活性炭吸附银的影响也是不同的。活性炭的氧化改性不利于Ag⁺和[Ag（S₂O₃）₂]^3-的吸附，却有利于[Ag（NH₃）₂]⁺的吸附。活性炭表面预吸附有机物（如茜红素等）后，对银的吸附性能均比原炭明显增强：活性炭表面经水合肼还原处理后，对银的吸附性能却无明显变化。 银主要分布在活性炭的外表面。银的分布受到吸附时间、银离子浓度、氧化改性及配位体等因素的影响。 具有氧化性的银离子在活性炭表面上的吸附机理是还原吸附。更多还原

【Abstract】 Activated carbon supporting silver has been widely used in water treatment and catalyst. The adsorption and distributing of silver on activated carbon were studied. The study results indicated: (1) Adsorption of silver on activated carbon was not influenced by the ion intensity in solution but ligand or surface oxidation modification of activated carbon with nitric acid and hydrogen peroxide. Ammonia had different influence on adsorption of silver from sodium thiosulfate. Surface oxidation modification of activated carbon made against adsorption of Ag+ and [Ag(S2O3)2]3-, but made for that of [Ag(NH3)2]+. Organic compound adsorbed on activated carbon significantly increased the reduction capacities of activated carbon for silver ion. After activated carbon was soaked in reducing agent (20% N2H4H2O) for three hours, the reduction capacity of activated carbon for silver ion did not change. (2) Silver on activated carbon mainly distributed outside. The difference of concentration of silver ion and the adsorption time resulted in different distributing of silver. When silver ion formed coordination compound or after activated carbon was modified with nitric acid and hydrogen peroxide, the distributing of silver on activated carbon changed. (3) X-ray diffraction pattern of activated carbon supporting silver showed that silver ion was deoxidized to elemental crystal on activated carbon. The adsorption and distributing of silver also testified indirectly the reduction of silver ion on activated carbon.更多还原