Preparing And Adsorption-Photocatalysis Property Of Titanium Dioxide Loaded Natural Maifan Stone

Abstract: The composite photocatalysts of TiO₂loaded natural maifan stone （TiO₂/Maifanstone） were obtained by a sol-gel method after heat treatment. The samples werecharacterized in detail by N2adsorption-desorption, XRD and IR. A variety of factors of thephotocatalytic activity of TiO₂/Maifan stone were discussed as follows: annealing temperature,dosage, pH value, initial concentration, additional oxidant, etc. So a new way was discoveredto develop and optimize the photocatalytic efficiency of TiO₂.In a self-made degradation device, the photocatalytic activity of photocatalyst has beenevaluated by decolorization ratio of the Rhodamine B, moreover, according to the lightdegradation curve of the Langmuir adsorption equation derived dynamics equation, it isconcluded that dynamics characteristics of loaded TiO₂light degradation of rhodamine B is aquasi-first order reaction. At lower concentrations, the initial concentration of rhodamine Bsolution is related to degradation rate, and with initial concentration, and the reaction velocityincreases with the decrease of the initial concentration.The reaction tends to the first orderreaction at lower concentration, and tends to zero order reaction at higher concentration. Theprepared product applied in the degradation of ammonia nitrogen pollutants in aqueoussolution. The optimal conditions of the photocatalytic activity of the composite photocatalystand the photocatalytic mechanism of ammonia nitrogen were also analyzed.The results show that, the loaded TiO₂/Maifan stone compound has the most lightcatalytic activity in the conditions of400℃calcination, and can reach the maximalphotocatalytic activity with the same effect of pure TiO₂. The best loading amount of TiO₂isabout4.5%or so. At the meantime, the transformation ratio of ammoniacal nitrogen is greatlydependent on its existence form in the solution, and the pH value is greater than7,ammoniacal nitrogen as the form of NH3will be beneficial to the reaction, and thedegradation ratio increases with the increasing of the pH value. In the pH=6, the degradationof Rhodamine B is best. In addition, the oxidant H2O₂is added, the photocatalytic effect ofthe photocatalyst is improved.