Introduction of a Pore Connection Network into Mesoporous TiO 2 Films to Enhance CO Gas Sensitivity

Abstract

© 2015 The Electrochemical Society. In thiswork, ordered mesoporous TiO < inf > 2 films with interior pore connections were fabricated. To introduce the interior pore connections, the grain growth of TiO < inf > 2 on the pore wall structure was controlled by increasing the annealing time. In the annealing process, the growth of TiO < inf > 2 grains was enhanced, and interior pores were connected by a meso-channel formed during the growth of TiO < inf > 2 grains. As a result, with increasing annealing time, the specific surface area of the mesoporous TiO < inf > 2 films increased by a factor of 3, although the porosity decreased. When the ordered mesoporous TiO < inf > 2 film with enhanced pore connectivity was applied in a CO gas sensor, the gas sensitivity increased by a factor of almost 20 due to the enhanced pore connectivity resulting from controlled annealing time. The introduction of pore connectivity in a closed pore structure may be an advantageous method in various fields where a large surface area is required for nanoporous structured materials.