Synthesis of morphology controllable porous Co3O4 nanostructures with tunable textural properties and their catalytic application.

Porous cobalt oxide (Co3O4) nanorod (50-100 nm) and nanosheet-like (70-100 nm) particles were synthesized by a facile hydrothermal method at 150 °C for 2-5 h and 12-24 h, respectively, using aqueous-based precursors like cobalt nitrate, urea and water in the absence of any templating agents followed by their calcination at 300 °C. Morphology and textural properties were tuned by changing the synthesis time at 150 °C. A 3D architecture of Co3O4 was formed by the self-assembly of nanostructured (nanorod and nanosheet) particles. The BET surface area, pore volume and pore diameter of the sample prepared at 150 °C for 5 h were 112 m(2) g(-1), 0.5 cm(3) g(-1) and 7.4 nm, respectively, and it exhibited the highest catalytic performance with a rate constant of 56.8 × 10(-3) min(-1) for the degradation of Chicago Sky Blue 6B, a carcinogenic azo dye used in the textile, paper and food industries. Rod-like particles with a mesoporous structure rendered a better catalytic efficiency than sheet-like particles having both microporous and mesoporous structures. An interrelationship amongst the morphology, textural properties and the catalytic efficiency of Co3O4 was established.