Volatile organic compounds gas sensing properties of ZnO nanorings

Hexagonal ZnO ring-like nanostructured powder was successfully synthesized by a facile sono-chemical process and the following etching treatment at room temperature without any catalysts or templates. The results indicated that the nanorings had a diameter of about 180 nm and wall thickness of about 50 nm. Nanorings gas sensor was fabricated on a silicon-based substrate with electrodes and heater prepared by MEMS process. Gas sensing measurements toward VOC gases (benzene, toluene, ethanol and acetaldehyde) indicated that the ZnO nanorings sensor possess excellent sensitivity to these gases. The promising gas sensing properties of ZnO nanorings sensor are due to the high active area and easy diffusion provided by the particular ring-like structure.