School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
Dalton Trans. 2018 Jun 19;47(24):7941-7948. doi: 10.1039/c8dt01151f.
SrAl2O4:Eu2+,Dy3+ long afterglow phosphors with one-dimensional nanostructures were synthesized by a hydrothermal method followed by post-annealing, and subsequently CdS was uniformly coated on their surfaces by a sol-gel approach. The nanocomposite system can significantly enhance the photocatalytic activity for the degradation of methyl orange and hexavalent chromium under ultraviolet and visible light irradiation. After the modification treatment with a 1 : 2 molar ratio of CdS to SrAl2O4:Eu2+,Dy3+ nanophosphors, the degradation rate of methyl orange can increase by 2.5 times and reach a maximum of 96.3% under visible light illumination for 30 min. The enhancement of photocatalytic activity originates from the improvement of light usage efficiency due to the hole migration from SrAl2O4:Eu2+,Dy3+ phosphors to the CdS semiconductor and the reutilization of SrAl2O4:Eu2+,Dy3+ luminescence.
SrAl2O4:Eu2+,Dy3+ 长余辉荧光粉具有一维纳米结构，采用水热法合成，然后进行后退火处理，随后通过溶胶-凝胶法在其表面均匀包覆 CdS。纳米复合材料体系在紫外光和可见光照射下，能显著提高对甲基橙和六价铬的光催化降解活性。用摩尔比为 1:2 的 CdS 对 SrAl2O4:Eu2+,Dy3+纳米荧光粉进行修饰处理后，在可见光照射 30 分钟内，甲基橙的降解率可提高 2.5 倍，最大可达 96.3%。光催化活性的增强源于光利用效率的提高，这是由于空穴从 SrAl2O4:Eu2+,Dy3+ 荧光粉迁移到 CdS 半导体，以及 SrAl2O4:Eu2+,Dy3+ 发光的再利用。
