Calcination system-induced nanocasting synthesis of uniform Co3O4 nanoparticles with high surface area and enhanced catalytic performance
Abstract
Co3O4 catalytic materials with varying mesoporous periodicity and crystallinity have been successfully synthesized via a calcination system-induced nanocasting method. N-Co3O4 with uniform nanoscale morphology, high specific surface area, and large pore size distribution was obtained in an open system as a calcination process, while M-Co3O4 with long-range mesoporous periodicity and high crystallinity was synthesized using a closed system as the calcination condition. The control of the mesostructure and morphology was carried out by tuning the diffusion rate of the cobalt precursor in the template channel resulting from the different escape rates of the decomposed byproducts via the varied calcination containers. The CO oxidation testing indicated that N-Co3O4 exhibited better catalytic performance than that of M-Co3O4. The difference in activity could be attributed to the uniform nanoscale structure of N-Co3O4, which mesoporous M-Co3O4 lacked. N-Co3O4 had a better performance for CO oxidation due to the uniform nanoparticle structure, higher specific surface area, larger pore size distribution, abundant active oxygen species and Co3+ cationic species on the surface, which accelerated the adsorption and diffusion of reactant molecules and finally improved the reaction activity of N-Co3O4. The resulting catalytic behaviors lead to a better understanding of designing and using such metal oxides for a number of catalytic applications.