Facile Synthesis of Co3O4 with Different Morphologies via Oxidation Kinetic Control and Its Application in Hydrogen Peroxide Decomposition

Co3O4 nanoparticles (NPs) with tubular and hollow structures were successfully synthesized by the formation of CoOOH and subsequent high-temperature calcination in air. The as-synthesized Co3O4 retained the morphologies of CoOOH. Therefore, the key step for the synthesis of Co3O4 was the controllable preparation of CoOOH NPs with tubular and hollow structures, which were prepared through a facile strategy involving the oxidation of beta-Co(OH)(2) under strong basic conditions (template-free, aqueous solution, and mild temperature). The morphology of CoOOH was tuned by employing air and H2O2 as the oxidizing agents which possessed different oxidation abilities and thus resulted in different oxidation kinetics. The plausible formation mechanism of CoOOH NPs with tubular and hollow structures was both related to the Kirkendall effect. In contrast to the commercial Co3O4, the as-prepared Co3O4 NPs with tubular and hollow structures showed superior catalytic activities for the decomposition of H2O2. The reaction rate constants of the as-prepared Co3O4 NPs with tubular and hollow structures were over 100 times the value of the commercial one.