(1. 合肥工業(yè)大學 化工學院，合肥 230009；
2. 合肥工業(yè)大學 食品與生物工程學院，合肥 230009)
摘 要: 使用濃HNO3分別在常溫和沸騰狀態(tài)下對活性炭進行改性，用FTIR和N2吸附法對活性炭進行表面分析，使用AAS，SEM和XRD研究銀在活性炭表面的吸附和分布特征。研究結果表明：活性炭經(jīng)常溫濃HNO3改性后，比表面積和孔容都明顯提高，而經(jīng)沸騰濃HNO3改性后，比表面積和孔容卻明顯減小，但2種改性方式都使活性炭表面產(chǎn)生更多的含氧基團，為[Ag(NH3)2]+的吸附還原提供更多的活性點，從而使活性炭表面銀顆粒更加密集；常溫濃HNO3改性極大地促進了[Ag(NH3)2]+的吸附還原，當銀離子初始質量濃度為600 mg/L時，活性炭對銀的吸附量是原炭的5倍多；而活性炭沸騰濃HNO3改性使銀的吸附量略有下降，但銀顆粒卻更加細小而密集，有利于活性炭表面納米銀顆粒的形成。
關鍵字: 活性炭；銀；濃HNO3；改性；吸附
HNO3 at different temperatures
on silver adsorption
（1. College of Chemical Engineering, Hefei University of Technology,
Hefei 230009, China;
2. College of Biology and Food Engineering, Hefei University of Technology,
Hefei 230009,China）
Abstract:Activated carbon (AC) was modified by concentrated nitric acid at room temperature and under boiling condition. The AC was characterized by FTIR and N2 adsorption technique. The adsorption and distribution of silver on AC were investigated by AAS, SEM, XRD for the preparation of AC supported with silver(AC/Ag). The results show that the surface area, micropore and mesopore volumes of carbon modified at room temperature increase, but those of carbon modified under boiling condition decrease greatly. The surface groups of AC modified at room temperature and under boiling condition (especially C—O, C=O) increase greatly, which makes silver granule on activated carbon become dense. The modification at room temperature increases the silver ion adsorption and reduction by more than 5 times when the concentration of silver ion is 600 mg/L. The modification under boiling condition makes silver granule become small and dense very much, and avails to the formation of silver nanoparticles on surface of activated carbon.
Key words: activated carbon; silver; concentrated nitric acid; modification; adsorption
