Crystallography facet tailoring of carbon doped ZnO nanorods via selective etching.

Using a facile hydrothermal method, we have successfully synthesized carbon doped (C-doped) ZnO nanorods with standard hexagonal column shapes. To modify their photocatalytic activities by tailoring the surfaces, a post etching process under ammonia atmosphere was used, and these nanorods could be converted into hexagonal porous nanorods (at 750 °C), and porous nanorods with corrugated surface structures covered by alternant ( 11 2 ¯ 1 ) and ( 11 2 ¯ 1 ¯ ) planes (at 850 °C and 950 °C). Energy Dispersion Spectrum and Raman spectra are used to carefully study the concentration and vibration modes of the doped carbon species. It explicitly shows that there is a carbonation process around 750 °C and some organic aldehyde molecules transform into carbon with flake form. After investigating their photoluminescence spectra and photocatalytic activities, we conclude that an appropriate etching temperature is the key point to obtain high photocatalytic performance. [ABSTRACT FROM AUTHOR]