Improving TiO2 gas sensing selectivity to acetone and other gases via a molecular imprinting method

Abstract

Various gas sensors have made considerable improvement in the quality of people's life. However, in most cases, changing materials is necessary for adapting the changing of target gas, which limits the further application of gas sensors. To meet this challenge, in this work, molecular imprinting (MI) technology is introduced. Acrylic acid is used as a functional monomer while gas molecules, including acetone, are used as templates. MI process with acetone template helps improve the acetone selectivity of TiO2 to 1.74-2.80 times. Moreover, it proved that other templates can increase the corresponding selectivity to at least 1.5 times by using the same matrix material. These results demonstrate potential importance of the MI process in constructing a highly compatible gas sensor industry. Beyond this, MI process has proved to achieve an ultrahigh specific surface area of 384.36 m2g-1. The optimal acetone sensor exhibits desirable comprehensive performance as compared with other reports. An excellent TiO2 based prototype acetone sensor working at 300 °C with a low detection limit of 18 ppb is obtained.