Preparation of HPA/Bi2WO6 and its photocatalytic properties for denitrification

The HPA/Bi2WO6 was prepared with Na2WO4·2H2O, Bi(NO3)3·5H2O and different surfactant templates. The prepared sample was dried by the supercritical fluid drying (SCFD) method. It was characterized with XRD, FT-IR and SEM techniques and N2 sorption experiment. Its photocatalytic properties were evaluated with denitrification of nitrogen-containing simulated oil as model reaction. It was shown that the sodium dodecyl sulfate (SDS) should be chosen as template. With this template, a highly dispersed, crystalline and active photocatalyst was obtained. This catalyst had a larger specific surface area. The SCFD method effectively decreased pore collapse and particles agglomeration degree, consequently increasing the specific surface area and improving the catalytic performance. Immobilization of H3PW12O40 on Bi2WO6 increased the surface acid sites, and hence the photocatalytic activity. When the H3PW12O40 loading was 10%, about 92.08% of nitrogen in simulated oil were removed by shining for 3 h with a xenon lamp at the mcatalysts/msimulated oil ratio of 1:100.