Synthesis of solid solutions of Cd_1−xZnxS nanocrystals in the channels of mesostructured silica films

Abstract

In this contribution, we introduce the use of metal ion (Cd(II) and Zn(II)) modified mesostructured silica as a reaction medium, to produce a solid solution of Cd1−xZnxS nanocrystals as a thin film. With this approach, a true liquid crystalline templating (TLCT) and liquid crystalline mesophase of transition metal salt ∶ oligo(ethylene oxide) non-ionic surfactant (((1 − x)[Cd(H2O)4](NO3)2 + x[Zn(H2O)6](NO3)2) ∶ CH3(CH2)11(OCH2CH2)10OH, (MLC)), systems were collectively used to synthesise mesostructured silica films. The film samples were reacted at room temperature (RT) in an H2S atmosphere to produce zinc blend Cd1−xZnxS nanocrystals in the channels of mesostructured silica. The initial Zn(II) and Cd(II) ion concentrations in the reaction media determine the final composition and band gap of the Cd1−xZnxS nanocrystals. The growth process of the Cd1−xZnxS nanocrystals in the pores is influenced by the silica walls. If the walls are rigid (well polymerized, obtained by aging the samples before H2S treatment), then the Cd1−xZnxS nanoparticles are smaller in size and more uniform in size distribution.