Studies On (SBA-15)-AgI Nanocomposite Material

SBA-15 molecular sieve owned the characteristic of uniform nanoscale channels, large pores, thick walls and high hydrothermal stability. It has the potential foreground as adsorption, separation, catalysis and new type host-guest nanocomposite materials.In this thesis, SBA-15 molecular sieve was synthesized in acidic medium by hydrothermal method using triblock copolymers (EG₂₀PG₄₀EG₂₀) as template, tetraethoxysilane as silica resource. Semiconductor material AgI was incorporated into the mesoporous channels of the SBA—15 molecular sieve by solid phase thermal diffusion method and the (SBA-15) - AgI nanocomposites materials were prepared. The products were characterized by means of chemical analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, low-temperature nitrogen adsorption-desorption technique at 77 K, scanning electronic microscopy, and luminous properties were studied. The results showed that AgI went into the channels of the SBA—15, the materials (SBA-15) - AgI remained the highly ordered two-dimensional hexagonal. However, the crystalline was decreased to some degree, the pore volume, pore size and the surface area decreased to some extent compared to those of the SBA-15 molecular sieve. For the infrared peaks of the composite materials blue shift took place. The larger the amount of the AgI incorporated, the greater the effect on the frameworks of the prepared materials. The morphology of (SBA-15) - AgI nanocomposite materials mainly presented fiber form. For the sample with the content of 12% AgI, the mean particle diameter of the (SBA—15)—AgI was 340±5 ran. It was found by luminous studies that the energy band gap of the (SBA—15)—AgI composite material is very high and radiation process is very strong. The composite materials possess very good luminous performance and can be hopefully acted as luminous materials.