One-dimensional porous Co3O4 rectangular rods for enhanced acetone gas sensing properties

One dimensional porous Co 3 O 4 rectangular microrods (MR) are designed and successfully prepared by a distinctive electrospun precursor-hydrothermal regulation-annealing treatment strategy while Co 3 O 4 nanofibers (NF) are also synthesized for comparison by directly calcining precursors without hydrothermal treatment. The hydrothermal treatment before annealing process results in morphology and structure transition of Co 3 O 4 products from compact solid nanofibers to porous rods. When applied as a gas sensing material, Co 3 O 4 porous rods based sensors exhibit enhanced gas sensing properties in terms of rapid response time (3 s), recovery time (5 s), good selectivity and stability towards 100 ppm acetone gas at a relatively low working temperature of 200 °C. Meanwhile, the response of Co 3 O 4 porous rods toward 100 ppm acetone reaches approximately 5 times higher than that of solid Co 3 O 4 nanofibers. The enhanced acetone gas sensing properties of Co 3 O 4 rectangular porous rods are believed to originate from its porous structure and large surface area, facilitating gas adsorption and surface reaction and causing significant change in the thickness of holes accumulation layer (HAL). Feasible morphology-adjusting strategy and enhanced acetone gas sensing performances further highlight the advantage of as-prepared Co 3 O 4 porous rods in future acetone real-time monitoring.