Enhanced ethanol sensing and mechanism of Cr-doped ZnO nanorods: Experimental and computational study

The pristine and Cr-doped ZnO nanorods were successfully synthesized via a facile hydrothermal route. We found that the ethanol gas response of ZnO was improved significantly by Cr doping. In particular, the enhanced gas-sensing mechanism was investigated by first-principles calculations upon proposed surface adsorption models. The calculated results revealed that the Cr-doped ZnO (0 0 0 1) surface enabled transfer larger electrons and adsorb more oxygen molecules than that of undoped one, thus holding the potential for further enhancement in gas response of ZnO-based sensors.