Large-scale syntheses of uniform ZnO nanorods and ethanol gas sensors application

Uniform ZnO nanorods with a gram scale were prepared by a low temperature and solution-based method. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL). The results showed that the sample had uniform rod-like morphology with a narrow size distribution and highly crystallinity. Room-temperature PL spectra of these nanorods show an exciton emission around 382 nm and a negligible deep level emission, indicating the nanorods have high quality. The gas-sensing properties of the materials have been investigated. The results indicate that the as-prepared nanorods show much better sensitivity and stability. The n-type semiconductor gas sensor exhibited high sensitivity and fast response to ethanol gas at a work temperature of 400 °C. ZnO nanorods are excellent potential candidates for highly sensitive gas sensors and ultraviolet laser.

Research highlights▶ The uniform ZnO nanorods could be synthesized by a low temperature, solution-based method. ▶ The results showed that the sample had uniform rod-like morphology with a narrow size distribution and highly crystallinity. ▶ Room-temperature photoluminescence spectra of these nanorods show an exciton emission around 382 nm and a weak deep level emission, indicating the nanorods have high quality. ▶ The sensor exhibited high sensitivity and fast response to ethanol gas at a work temperature of 400 °C.