Synthesis of bentonite/Nano-Mn3O4 composite material and degradation of formaldehyde

Abstract

In order to obtain more efficient catalytic materials for degrading the air pollutant - formaldehyde, Nano-Mn3O4 and bentonite / Nano-Mn3O4 composite catalysts (BMC) for formaldehyde degradation were prepared by sol gel method, using manganese sulfate, bentonite, citric acid and ammonia as reactants. Field emission-scanning electron microscope, Transmission electron microscope, X-ray Diffraction, Nitrogen adsorption experiments and laser particle size analyzing instrument have been employed to characterize the Mn3O4 and BMC nanoparticles, respectively. The mechanism and effect of formaldehyde degradation of these substances are also discussed. The results show that BMC catalytic material has a better ability to degrade formaldehyde in air than Mn3O4 at the room temperature, which is resulted by the strong adsorption capacity of bentonite providing a reaction site and molecular collision site for oxidative decomposition of formaldehyde. And the synthesized catalytic materials have the advantages of low cost, easy regeneration and recycling.