HMT assisted hydrothermal synthesis of various ZnO nanostructures: Structure, growth and gas sensor properties

ZnO nanocrystals with various morphologies are synthesized via a simple and facile HMT assisted hydrothermal process. Here, HMT is introduced as a structure directing and assembling agent to controllable synthesis of ZnO architectures and the concentration of HMT play a critical role in producing such different ZnO morphologies. We find that the sandglass-like ZnO exhibit excellent sensing performances to the target ethanol gas owing to its largest amount of Zn-terminated ZnO (0001) polar surfaces, which can easily adsorb more oxygen species on the surface and therefore improve the gas-sensing performances of ZnO. Such an unexpected morphology holds substantial promise for rendering ZnO as a potential gas-sensing material for future sensor applications.