Various sizes and shapes of Mn_(3)O_(4) nanocrystals have been prepared in a one-pot synthesis in extremely dilute solution by soft template self-assembly. To better control size and shape, the effects of varying the ...Various sizes and shapes of Mn_(3)O_(4) nanocrystals have been prepared in a one-pot synthesis in extremely dilute solution by soft template self-assembly. To better control size and shape, the effects of varying the growth time, reaction temperature, surfactant, and manganese source were examined. The average size of octahedral Mn_(3)O_(4) crystallites was found to be related to the reaction time, while higher reaction temperature (150 °C) and the use of a cetyltrimethylammonium bromide/poly(vinylpyrrolidone) (CTAB/PVP) mixture allowed construction of a better-defined octahedral morphologies. When PVP or poly(ethylene oxide)-poly(propylene oxide) (P123) was used as template, large-scale agglomeration resulting in loss of the octahedral morphology occurred and crystallites with a quasi-spherical shape were obtained. The nano-octahedral crystallites were shown to be an efficient catalyst for the oxidation of methylene blue.展开更多
基金This work was financially supported by the Chinese Ministry of Science and Technology(Project Nos.2006BAE02B05 and 2005CB221406).
文摘Various sizes and shapes of Mn_(3)O_(4) nanocrystals have been prepared in a one-pot synthesis in extremely dilute solution by soft template self-assembly. To better control size and shape, the effects of varying the growth time, reaction temperature, surfactant, and manganese source were examined. The average size of octahedral Mn_(3)O_(4) crystallites was found to be related to the reaction time, while higher reaction temperature (150 °C) and the use of a cetyltrimethylammonium bromide/poly(vinylpyrrolidone) (CTAB/PVP) mixture allowed construction of a better-defined octahedral morphologies. When PVP or poly(ethylene oxide)-poly(propylene oxide) (P123) was used as template, large-scale agglomeration resulting in loss of the octahedral morphology occurred and crystallites with a quasi-spherical shape were obtained. The nano-octahedral crystallites were shown to be an efficient catalyst for the oxidation of methylene blue.