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

Abstract

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 m² g⁻¹, 0.5 cm³ 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.