Investigation of removal of HCHO by Zn modified Co3O4 catalyst at room temperature

In this paper, removal of formaldehyde on Zn-modified Co3O4 catalyst under room temperature was investigated. The performance tests on different zinc nitrate molar concentration doped catalysts which were prepared by the hydrothermal method demonstrated that the catalyst shows excellent HCHO removal performance when the zinc nitrate molar concentration was 0.6 (Zn0.6CoO). The effects of Zn addition on the structure and activity of the Co3O4 catalyst was studied by X-ray diffraction, Fourier transform infrared spectroscopy, N2-absorption/desorption, Raman, scanning electron microscopy, a transmission electron microscope and X-ray photoelectron spectroscopy. The results showed that Zn is doped into the lattice of Co3O4 and caused lattice distortion, which should be the key to increase the oxygen vacancy concentration. In addition, doping Zn improves the specific surface area of the Co3O4 catalyst, which indirectly provides more active sites for HCHO, and the activity of Zn0.6CoO catalyst with high oxygen vacancy concentration is higher than Co3O4 nanobelts, which indicates that doping Zn enhances the HCHO removal performance by increasing the oxygen vacancy content.