Tailoring the surface morphology of nanostructured cobalt oxide for high-sensitivity CO sensor

The development of efficient carbon monoxide (CO) gas sensors with earth abundance and low cost is very important in gas sensing applications. The cobalt oxide material with various morphologies and structures demonstrates different gas sensing properties. In this work, different morphologies of nanostructured spinel cobalt oxide (Co3O4) have been synthesized by pulsed laser ablation in liquid media (PLAL) using high-purity cobalt as a target in several ethanol/water mixtures. The gas properties of the fabricated Co3O4-based sensors were investigated toward CO gas at various gas concentrations and operating temperatures. Several characterization techniques including TEM, XRD, XPS, and Raman spectroscopy were utilized to study the chemical and physical properties of the fabricated samples. The obtained results displayed that the morphology of the nanostructured Co3O4 could be controlled by altering the ethanol concentrations in the ablation media. Compared with the Co3O4 nanoparticles prepared by laser ablation in water, the Co3O4 nanosheets/flakes prepared at 70% ethanol exhibited superior sensitivity characteristics. A sensitivity of 360% was achieved at 300 degrees C and 200 ppm of CO. These results reordered for Co3O4 nanosheets/flakes demonstrate a brand-new approach for the fabrication of low-detection-limit CO sensors.

Automated summary

In this study, nanostructured spinel cobalt oxide with different morphologies were synthesized using pulsed laser ablation in liquid media. The gas sensing properties of the fabricated sensors towards CO gas were investigated, and the results showed that Co3O4 nanosheets/flakes prepared at 70% ethanol exhibited superior sensitivity characteristics.