RESUMO
Porous C3N4(PCN) is favored by researchers because it has more surface active sites, higher specific surface area and stronger light absorption ability than traditional g-C3N4. In this study, cerium dioxide nanoparticles (CeO2-NPs) with mixed valence state of Ce3+and Ce4+were doped into the PCN framework by a two-step method. The results indicate that CeO2-NPs are highly dispersed in the PCN framework, which leads to a narrower band gap, a wider range of the light response and an improved the separation efficiency of photogenerated charge in PCN. Moreover, the specific surface area (145.69 m2g-1) of CeO2-NPs doped PCN is a 25.5% enhancement than that of PCN (116.13 m2g-1). In the experiment of photocatalytic selective oxidation of benzyl alcohol, CeO2-NPs doped porous C3N4exhibits excellent photocatalytic activity, especially Ce-PCN-30. The conversion rate of benzyl alcohol reaches 74.9% using Ce-PCN-30 as photocatalyst by 8 h of illumination, which is 25.7% higher than that of pure porous C3N4. Additionally, CeO2-NPs doped porous C3N4also exhibits better photocatalytic efficiency for other aromatic alcohols.
RESUMO
OBJECTIVE: To make comparative study on HPLC-FPS of several kinds of Pueraria lobata and P. thomsonii from different sources. METHOD: Kromasil C18 column was used, with mixture of acetonitrile and water as mobile phase in a gradient mode. The wavelength of measurement was 250 nm. RESULT AND CONCLUSION: The fingerprints of P. lobata and P. thomsonii were obtained. This method can be used to identify P. lobata and P. thomsonii from different sources conveniently, and it may be practically valuable for the quality control of sample for P. lobata or P. thomsonii and its preparation.
