Study On Preparation And Photocatalytic Properties Of Metal Doped Aluminophosphate Molecular Sieves

Metal doped aluminophosphate molecular sieves were prepared by hydrothermal synthesis starting from phosphoric acid and pseudo-boehmite as the source of phosphorus and aluminum, using triethylamine as organic template, and in-situ mixed with magnesium sulfate or nickel sulfate or manganese sulfate or ferric nitrate or zinc acetic. Then, they were crystallized at a certain temperature and time. The products were characterized by XRD, SEM, XRF, FT-IR, UV-Vis-DRS and so on. Their photocatalytic activities were evaluated by the photodegradation of methyl orange under ultraviolet irradiation and the photodegradation of methylene blue under visible light. At the same time, the impact on visible light degradation of methylene blue was studied under the different prepare conditions of catalyst such as crystallization time, organic template, pH and photocatalytic reaction conditions such as different catalyst amount, taking MgAPO-5 molecular sieve as the representative sample. The primary results showed that, all of the samples had the same structure as aluminophosphate molecular sieves, the doped element Mg, Ni, Mn, Fe and Zn might enter the framework of the molecular sieves, respectively; it also revealed well photocatalytic activity of samples on methyl orange and methylene blue. The decolour rate of the methyl orange solution was 83.7% with MgAPO-5 molecular sieve under UV illumination, and the decolour rate of the methylene blue solution was 92.5 % with MgAPO-5 molecular sieve under visible light. The photocatalytic activity of samples on methylene blue was to some extent affected by the different prepare and photocatalytic reaction conditions.