Mcm-41 The Surface Bimetallic Composite Materials Preparation, Characterization And Photocatalytic Performance

The semiconductor photocatalytic materials are attracting extensive attentions because of their splendid application prospects in the field of energy, environment and other spots fields. However, this type of catalysts prepared by traditional processes has low activities on comparison with our aspects. In this thesis, based on the method of Surface Organometallic Chemistry (SOMC), we prepared a series of catalytic materials that have clear compositions, structures and special performances by chemical grafting a few organometallics on the mesoporous molecular sieve MCM-41carrier, with subsequent high-temperature calcinations under oxygen-rich atmosphere. In this thesis, after introduction of the development of SOMC and progress of semiconductor photocatalysts, the catalytic materials with single metal active centers or bimetallic active centers are prepared with Schlenk techniques, and the surface compounds on MCM-41were characterized by in suit FTIR, SEM, EDAX, XPS, TG-DTA. The photocatalytic degradation activities of as-prepared materials were then investigated using methyl orange as model. The main contents are as follows:1. After the activation of molecular sieve MCM-41at vacuum, it is founded that different forms of hydroxyl groups on the surface of molecular sieve MCM-41were observed when activated at different temperatures. The isolation distribution of hydroxyl groups was observed when activated at550℃.2. Taking tetrakis(dimethylamino) titanium, tetrakis(dimethylamino), and1,1'-ferrocenedicarboxylic acid as precursors, the target products singe-active-site materials (MCM-41-TiO2and MCM-41-ZrO2) and double-active-site materials (MCM-41-TiO2/Fe2O3and MCM-41-ZrO2/Fe2O3) were obtained by chemical grafting reaction with activation at550℃. The prepared compounds were characterized by in suit FT-IR, SEM, EDAX, XPS, TG-DTA. The results showed that the precursors were successfully grafted to the carrier surface.3. Using methyl orange as an azo dye model, the photocatalytic degradation properties of both singe-active-site materials (MCM-41-TiO2and MCM-41-ZrO2) and double-active-site materials (MCM-41-TiO2/Fe2O3and MCM-41-ZrO2/Fe2O3) for azo dyes were investigated. The primary results showed that the catalytic activities of the singe-active-site materials are higher than those of the double-active-site materials.