Fengfeng Li

Effect of pH and molar concentration on photocatalytic performance of BiVO4 synthesised by sol–gel method

In this study, a series of monoclinic BiVO4 photocatalysts were successfully synthesised by the sol–gel method by varying pH and molar concentration. The structural and morphological properties of the synthesised BiVO4 photocatalysts were characterised by X-ray diffraction and scanning electron microscopy, respectively. The photocatalytic activity of the catalysts was evaluated by the degradation of RhB under visible-light irradiation. The results indicate that at pH = 7, the catalysts showed the best photocatalytic activity, reaching up to 90.9%. Furthermore, at 0.2M concentration, the catalysts showed the best photocatalytic activity, reaching up to 89.4%. The catalysts synthesised at different pH and molar concentrations exhibited different photocatalytic activities under visible-light irradiation because different conditions led to different degrees of crystallinity and grain distributions of monoclinic BiVO4.

Study on Sr2MgSi2O7:Eu2+,Dy3+ Long-Afterglow Luminescent Materials Via Sol-Hydrothermal Synthesis

ABSTRACT In this study, Sr2MgSi2O7:Eu2+,Dy3+ long-afterglow luminescent materials have been successfully prepared via sol-hydrothermal method. The sample shows good crystallinity and optical properties. The sintering time and sintering temperature have great impacts on the crystallization process and luminescence properties. Further, adding of H3BO3 has been found to be good for formation of Sr2MgSi2O7:Eu2+,Dy3+ and appropriate amount of H3BO3 addition helps to improve the performance of the sample afterglow. Crystallization of the samples can be improved by changing the sintering system and method. GRAPHICAL ABSTRACT

Luminescent Properties of ZnxCa1–xTiO3:yPr3+ Long-Lasting Phosphors

Abstract The red long-lasting phosphors (LLPs) ZnxCa1–xTiO3:yPr3+ (ZCTP) were successfully prepared via the sol–gel method. The effects of Zn2+ content and Pr3+ molar concentration on the luminescent properties of ZCTP LLPs were characterized by X-ray diffraction, excitation and emission spectra, long-lasting decay curves and thermoluminescence (TL) curves. In this study, the results indicated that luminescent properties of Zn0.2Ca0.8TiO3:0.2 %Pr3+ phosphor was the best. In addition, when Pr3+ molar concentration reached 0.8 mol %, concentration quenching effect was obvious.

Influence of Heat Treatment on Photocatalytic Performance of BiVO4 Synthesized by Hydrothermal Method

Abstract Monoclinic BiVO4 photocatalyst was successfully synthesized by hydrothermal method under appropriate temperature. The photocatalytic performance of BiVO4 was improved by calcining at appropriate temperature. The structural and morphological properties of the synthesized BiVO4 photocatalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It is confirmed that the photocatalytic activity of the prepared catalysts was evaluated by the photodegradation of RhB under visible-light irradiation. BiVO4 calcined under appropriate temperature exhibited higher photocatalytic activity than uncalcined BiVO4 under visible light irradiation because calcination might effectively increases the purity of monoclinic bismuth vanadate.