Hierarchically porous Co3O4 hollow spheres with tunable pore structure and enhanced catalytic activity

Co3O4 hollow spheres with two-level hierarchical pores and high surface area are synthesized, and the shell thickness and the mesoporous structure are well-tuned through pre-treatment of the carbon spheres with alkali/acid. Evaluation of the Co3O4 hollow spheres for the combustion of CH4 reveals that they exhibit excellent catalytic activity and durability.