Mesopore engineering of Co₃O₄ nanoplates for enhanced detection of toluene vapor

It remains a significant challenge for efficient detection of toluene vapor because of the low chemical reactivity. In this paper, the Co3O4 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 Co3O4 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 degrees C). The improved toluene-sensing can be tracked from suitable mesopore size and specific catalytic activity of the Co3O4 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.