Photoluminescence of Zn5(CO3)2(OH)6 nanoparticles synthesized by utilizing CO2 and ZnO water slurry

Zinc carbonate hydroxide, Zn-5(CO3)(2)(OH)(6), nanoparticles were conveniently synthesized from zinc oxide (ZnO) fine powders and photoluminescence of the synthesized Zn-5(CO3)(2)(OH)(6) powder was investigated. The synthesized fine ZnO powder was mixed in water to prepare a ZnO slurry. The ZnO slurry was then reacted with CO2 at 25 degrees C to produce Zn-5(CO3)(2)(OH)(6). The amount of Zn-5(CO3)(2)(OH)(6) increased as the mass ratio of water/ZnO and the time of the reaction of CO2 with the ZnO slurry was increased. The synthesized Zn-5(CO3)(2)(OH)(6) powder exhibited a strong blue-purple emission at around 375 nm under UV-light excitation at 286 nm, while the fine ZnO powder exhibit a weak red-purple emission at around 425 nm under UV-light excitation at 258 nm. The intensity of the blue-purple emission was increased with increasing the amount of Zn-5(CO3)(2)(OH)(6). The emission spectra of Zn-5(CO3)(2)(OH)(6) was different from ZnO and other zinc carbonate hydroxides such as Zn4CO3(OH)(6) center dot H2O. The blue-purple emission, owing to Zn-O charge transfer transition of the Zn-5(CO3)(2)(OH)(6), was increased with increasing UV absorption intensity of electron transitions in CO32- of Zn-5(CO3)(2)(OH)(6). Thus, the Zn-5(CO3)(2)(OH)(6) nanoparticle obtained by the conventional and novel synthesis method using ZnO and CO2, exhibit a strong blue-purple emission because of the crystal structure of Zn-5(CO3)(2)(OH)(6) having ZnO4 and CO32-.