Mesopore engineering of Co3O4 nanoplates for enhanced detection of toluene vapor.

[Display omitted] • Varied mesopore widths (5.1, 12.6, and 19.8 nm) of Co 3 O 4 nanoplates are achieved. • The Co 3 O 4 with 5.1 nm of mesopore width shows highest R g /R a value to toluene. • An actual detection limit is observed as low as 1 ppm. • Clear toluene selectivity against other gases is obtained. It remains a significant challenge for efficient detection of toluene vapor because of the low chemical reactivity. In this paper, the Co 3 O 4 nanoplates with various mesopore widths (5.1, 12.6, and 19.8 nm) onto their surfaces have been successfully achieved using a simple hydrothermal and followed annealing route. Moreover, the sensor based on this Co 3 O 4 nanoplate with mesopore width of 5.1 nm presents an obvious toluene-sensing response (including actual detection limit of 1 ppm, and excellent selectivity) at a low working temperature (140 °C). The improved toluene-sensing can be tracked from suitable mesopore size and specific catalytic activity of the Co 3 O 4 nanoplates, which are advantageous for gas adsorption and diffusion, as well as facilitating the rapid oxidation of toluene gas. This work announces a reliable strategy to detect low reactive gas by constructing rational mesopores-width over the catalytic oxide. [ABSTRACT FROM AUTHOR]