Fabrication of porous Zn2TiO4–ZnO microtubes and analysis of their acetone gas sensing properties

Abstract

Porous Zn2TiO4–ZnO microtubes have been successfully fabricated using chemical precipitation followed by a calcination process using a carbon fiber template. The porous Zn2TiO4–ZnO microtubes with a diameter of ~ 4 μm consisted of Zn2TiO4 and ZnO nanoparticles. These displayed worm-like pore structures. Carbon fibers played an important role during the porous Zn2TiO4–ZnO microtube formation process. The porous and hollow structure of Zn2TiO4–ZnO provided abundant active sensing sites and channels for gas adsorption and diffusion. The porous Zn2TiO4–ZnO microtubes exhibited improved gas sensing properties for acetone when compared with pure ZnO. The Zn2TiO4–ZnO sensor response was 33.4 for 100 μg·ml−1 acetone at the optimum operating temperature (370 °C). This was ~ 2.7 times higher than that of pure ZnO. Additionally, the as-prepared porous Zn2TiO4–ZnO microtubes displayed sufficient long-term acetone stability and selectivity. This showed the potential application for acetone detection. The enhanced Zn2TiO4–ZnO gas sensing properties are due to the unique heterogeneous and porous structure, which was analyzed using the porous and band structure.