纳米YMn_2O_5半导体可见光催化剂

Nano YMn_2O_5 Visible-light-driven Semiconductor Photocatalyst

采用改进的聚丙烯酰胺凝胶法合成了YMn2O5纳米颗粒.XRD分析结果表明,合成的纳米颗粒主要为正交YMn2O5相,兼有少许的六方YMn2O5相,无其它杂质相存在.SEM观察显示,制得的YMn2O5纳米颗粒粒度均匀、形貌规整、呈类球形,平均颗粒尺寸约为45nm.利用紫外—可见光漫反射光谱研究了YMn2O5纳米颗粒的光吸收特性及带隙,获得的光学带隙值为1.21eV.以一种典型的偶氮染料甲基红为目标降解物,研究了YMn2O5纳米颗粒的光催化活性.结果表明,在紫外光和可见光辐照下纳米颗粒均表现出了良好的光催化活性.实验确定了光催化降解率的最佳条件:甲基红的初始浓度为～15mg/L,催化剂的加载量为～1.2g/L.

YMn2O5 nanoparticles were synthesized by a modified polyacrylamide Gel technique.X-ray diffraction（XRD） analysis indicated that the as-synthesized nanoparticles crystallized mostly into orthorhombic YMn2O5 phase and less into hexagonal YMn2O5 phase without the presence of any other impurities.Scanning electron mi-croscope（SEM） observation showed that the prepared YMn2O5 nanoparticles were regularly spherical in shape and highly uniform in size with a diameter of about 45nm.Ultraviolet-visible diffuse reflectance spectroscopy was used to investigate the light-absorbing properties and bandgap of YMn2O5 nanoparticles,and the value of the optical bandgap energy was obtained to be 1.21eV.The photocatalytic activity of YMn2O5 nanoparticles was investigated by the degradation of Methyl red（MR）,a typical azo dye.The experimental results revealed that the product exhib-ited a pronounced photocatalytic activity for the MR decomposition under ultraviolet and visible light irradiation.The optimum conditions for the photocatalytic degradation were determined to be as follows,initial concentration of MR,15mg/L,catalyst dosage,1.2g/L.