Optical Properties of Host(SBA‐15)‐guest(AgI) Composite Materials

Abstract

AbstractNanoclusters AgI have been prepared in the channels of SBA‐15 molecular sieve host, and the host‐guest nanocomposite materials were prepared by a heat diffusion method. The (SBA‐15)‐AgI host‐guest nanocomposites were characterized by powder X‐ray diffraction analysis, nitrogen adsorption‐desorption isotherms at 77 K, and solid‐state diffuse reflectance absorption spectra. The decrease in surface area, pore diameter, and pore volume showed the existence of silver iodide clusters in the channels of SBA‐15 host. X‐ray diffraction illustrates that the framework of the SBA‐15 remained in the host‐guest composites of (SBA‐15)‐AgI. As the guest loading decreases, a blue‐shift was observed in the diffuse reflectance spectra. This shows that the guest existed in the channels of SBA‐15 and a quantum confinement effect emerged. The photoluminescence (PL) spectra show that the PL at ∼2.38 eV, associated with the hydrogen‐related species, decreases substantially after the loading of AgI in SBA‐15. The decrease of the PL indicates the reduction of the hydrogen concentration on the pore surface of SBA‐15 after the loading of AgI guest. The intensity decrease of the self‐trapped exciton (STE) band at 2.76 eV also suggests a hindrance for generating the excitons upon adding the AgI guest into the SBA‐15 host.