Coating of ZnO nanoparticles onto the inner pore channel surface of SiC foam to fabricate a novel antibacterial air filter material

ZnO nanoparticles layer was successfully and firmly coated onto the surface of the pore channel of SiC foam via a sol-gel method in the presence of a negative pressure suction to fabricate a novel anti-bacterial air filter material. Composition, structure and morphology of the coated ZnO were characterized by scanning electron microscope, X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectronic spectroscopy. A possible formation mechanism of ZnO was proposed. A high crystallized ZnO nanoparticles layer was formed when the calcination temperature exceeds 500 °C. The coated ZnO crystallites were hexagonal wurtzite and the grain size was in the range of 20-50 nm. No evident N₂ permeability difference was detected in gas permeation tests before and after ZnO nanoparticles coating. ZnO-coated SiC foam was found to exhibit an excellent anti-bacterial property with sterilization rate of Escherichia coli exceeding 99.8% for all modified samples.