Constructing one dimensional Co3O4 hierarchical nanofibers as efficient sensing materials for rapid acetone gas detection

Abstract

The distinctive Co3O4 hierarchical nanofibers (Co3O4 HNF) is fabricated by annealing as-prepared PVA/Co(NO3)2·6H2O hierarchical nanofibers, which are synthesized by direct hydrothermal treatment of electrospun PVA/Co(NO3)2·6H2O nanofiber precursors without annealing process. In this way, the morphology, aggregation level and crystallinity of designed Co3O4 HNF can be well regulated during hydrothermal process. Microstructural characterization by means of scanning electron microscopy and X-ray diffraction demonstrates that numerous porous nanosheets almost perpendicularly grow on the surfaces of nanofibers, constructing distinctive Co3O4 hierarchical nanofibers. Such unique fiber-like hierarchical architectures provide efficient and convenient channels for the transmission of carriers and effectively convert chemical signals into electrical signals. As a result, Co3O4 HNF based sensors exhibit enhanced acetone gas sensing response in comparison with the common Co3O4 nanofibers (Co3O4 NF). Moreover, Co3O4 HNF shows rapid response (7 s) and recovery time (1 s) towards 100 ppm acetone gas at an optimal working temperature of 190 °C. This work may open up a facile and feasible approach for constructing hierarchical nanofibers to achieve high performance detection of acetone gas.