Co 3 O 4 nanosheets：synthesis and catalytic application for CO oxidation at room temperature

Hexagonal β-Co(OH)2 nanosheets with edge length of 50 nm and thickness of 10 nm were hydrothermally synthesized with the aid of triethylamine. Upon calcination at 350 °C in air, the β-Co(OH)2 nanosheets was converted into Co3O4 nanosheets with a similar dimension. Structural analyses during the calcination process identified that the β-Co(OH)2 precursor was initially dehydrated to HCoO2 and subsequently transferred into Co3O4. When being applied to catalyze CO oxidation at room temperature, the Co3O4 nanosheets exhibited a higher activity than the conventional spherical nanoparticles. This was perhaps related to the partial exposure of the {11\(\bar 2\)} planes over the Co3O4 nanosheets. The porous structure generated during the calcination process also provided significant amounts of surface defects, which might contribute to the enhanced catalytic activity as well.