ZnO micro-windbreak for enhanced gas diffusion

In this paper, a simple way is developed for the synthesis of the ZnO micro-windbreak film (ZMW) based on layered basic zinc salt precursor. The ZnO products maintain the original morphologies of precursors without deformation. Scanning electron microscopy, transmission electron microscopy, infrared spectrum and X-ray diffraction are used to characterize the detailed structures of the as-prepared products. Because of better gas diffusion in single layer ordered flower arrays (highly exposed surfaces) and thin belt-like branches (high diffusion coefficient) than other hierarchical structures, ZMW exhibits the highest responses to benzene gas. High responses allow ZMW to be used for the detection of benzene at ppb-level. By simply sputtering the platinum on both faces of ZMW to enhance the surface reaction, the optimal operating temperature for benzene detection could be reduced to 350 °C and the responses are significantly improved.