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.