A highly susceptive mesoporous hematite microcube architecture for sustainable P-type formaldehyde gas sensors

The mesoporous hematite cubic frameworks (alpha-Fe2O3 microcube) with 2-3 mu m sizes were prepared using a simple thermal treatment of the iron oxalate hydrate cubes (4 mu m). The alpha-Fe2O3 microcube structure with a high surface area (36 m(2) g(-1)) had three-dimensionally connected small grain sizes ((similar to)18 nm). In formaldehyde (HCHO) gas sensing, the fabricated device by alpha-Fe2O3 microcubes shows excellent detection ability even at low HCHO concentration ((similar to)50 ppb) and high response reaching to R-gas/R-air = 5.2 at 1 ppm as well as long-term stability, compared with conventional Fe2O3 nanoparticles.