Enhancement of photocatalytic property of ZnO for gaseous formaldehyde degradation by modifying morphology and crystal defect

We have improved the photocatalytic property of ZnO for gaseous formaldehyde degradation by modifying morphology and crystal defect. Six prisms (SP), short six pyramids (SSP) and long six pyramids (LSP) shape ZnO with different defect contents were prepared by the liquid phase method at low temperatures. The as-prepared ZnO were heat-treated with the gas mixture of Ar and H2 at 500 °C for 5 and 10 h. The defect states were characterized by multi-peaks Gaussian fitting of photoluminescence (PL) of ZnO. The degradation efficiency of LSP-10h ZnO under ultraviolet illumination was larger than that of commercial TiO2 (P25). The degradation efficiency of SP-10h ZnO under ultraviolet illumination was comparable to that of TiO2. The degradation efficiency of SP-10h ZnO and LSP-10h ZnO under white illumination were approached to that of TiO2. The relationships between the morphologies, the defect states and the photocatalytic properties of as-prepared ZnO were discussed in detail.

The photocatalytic property of ZnO for gaseous formaldehyde degradation was improved by modifying morphology and crystal defect. The degradation efficiency of LSP-10h ZnO under ultraviolet illumination was larger than that of commercial TiO2 (P25). The degradation efficiency of SP-10h ZnO under ultraviolet illumination was comparable to that of TiO2. The degradation efficiency of SP-10h ZnO and LSP-10h ZnO under white illumination were approached to that of TiO2. The relationships between the morphologies, the defect states and the photocatalytic properties of as-prepared ZnO were discussed in detail.Figure optionsDownload as PowerPoint slideHighlights
► ZnO with different shapes were prepared at low temperatures.
► Photoluminescence intensity of ZnO was lower after treating in Ar/H2.
► Defect states were characterized by Gaussian fitting of photoluminescence.
► Photocatalytic property of LSP-10h ZnO was better than that of TiO2 (P25).