Abstract
Co3O4 hollow spheres prepared by ultrasonic spray pyrolysis were converted into Co3O4-SnO2 core-shell hollow spheres by galvanic replacement with subsequent calcination at 450 °C for 2 h for gas sensor applications. Gas selectivity of the obtained spheres can be controlled by varying the amount of SnO2 shells (14.6, 24.3, and 43.3 at. %) and sensor temperatures. Co3O4 sensors possess an ability to selectively detect ethanol at 275 °C. When the amount of SnO2 shells was increased to 14.6 and 24.3 at. %, highly selective detection of xylene and methylbenzenes (xylene + toluene) was achieved at 275 and 300 °C, respectively. Good selectivity of Co3O4 hollow spheres to ethanol can be explained by a catalytic activity of Co3O4; whereas high selectivity of Co3O4-SnO2 core-shell hollow spheres to methylbenzenes is attributed to a synergistic effect of catalytic SnO2 and Co3O4 and promotion of gas sensing reactions by a pore-size control of microreactors. (Figure Presented).
Original language | English |
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Pages (from-to) | 7877-7883 |
Number of pages | 7 |
Journal | ACS Applied Materials and Interfaces |
Volume | 8 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2016 Mar 30 |
Keywords
- CoO
- SnO
- galvanic replacement
- gas sensor
- heterostructure
- methylbenzene
ASJC Scopus subject areas
- Materials Science(all)