活性碳纤维的氧化还原动力学研究

STUDIES ON THE REDOX KINETICS OF ACTIVATED CARBONFIBERS

The redox kinetics of activated carbon fibers (ACFs)reacting withAu_-~(3+) in various conditions are systematically investigated in this paper.The experimental results showed that the redox kinetic curves of ACFs canbe divided into three regions.In the first region,the concentration of Au_-~(3+)decreases very quickly.In the second region,there is a functional relati-onship between the concentration of Au_-~(3+) and time.In the third region,the concentration of Au_-~(3+) is linear with reaction time.Although the speedof redox reaction of ACF is slower than that of its physical adsorption,the redox capacity of ACF for Au_-~(3+) can reach approximately 900mg/g in2 hours.The conditions for preparing ACF and the innitial concentrationof Au_-~(3+) used in reaction do not obviously affect the kinetic characteristicof ACF.When the pH value of solution decreases,the reaction rate decr-eases after 1 hour.When the reaction temperature rises,the reaction rateincreases significantly.It should be pointed out that the change of reactiontemperature changes not only the constant of reaction rate in the thirdregion,but also the reaction order of the second region.It can be statedthat the redox kinetic of ACF may be comprised of the reaction kineticsof various centers together.