Y2Cu2O5 photocatalyst was successfully synthesized via solid state reaction and sol-gel method, respectively. The thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet visible diffuse reflectance absorption spectra (UV-Vis DRS) were employed to characterize the as-synthesized Y2Cu2O5 products. The photocatalytic H2 evolution activity of the as-obtained samples was evaluated from oxalic acid solution used as sacrificial reagent under simulated sunlight irradiation. The influences of synthesis methods and sacrificial reagent types on the photocatalytic H2 evolution activity and durability of the as-obtained photocatalyst were investigated in detail. The results show that the sample synthesized by sol-gel method is mixture of Y2Cu205 and Y2O3, while that synthesized by solid state reaction is pure Y2Cu2O5 photocatalyst that exhibits better photocatalytic H2 evolution activity. When the concentration of the photocatalyst synthesized by solid state reaction is 0.8 g/L, the oxalic acid is used as the sacrificial reagent, and the initial concentration is 0.05 mol/L, the highest photocatalytic H2 evolution activity (3.78 mmol/(h-g)) is obtained over the as-synthesized Y2G12O5 photocatalyst. But Y2CU2O5 photocatalyst is also unstable in the oxalic acid solution, and can change into Y2(C2O4)3"2H2O, which will decrease the photocatalytic H2 evolution activity.%分别用固相法和液相法制备Y2Cu2O5光催化剂,利用热重-差热分析(TG-DTA)、X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见光漫反射光谱(UV-Vis DRS)等技术对光催化剂进行表征.在模拟太阳光照射条件下,以草酸(H2C2O4)为牺牲剂对所制得的光催化剂制氢性能进行评价,考察制备方法和牺牲剂类型等因素对其产氢性能的影响以及光催化剂的稳定性能.结果表明:溶胶-凝胶法所得样品中含有Y2O3杂质,为Y2Cu2O5与Y2O3的混合物；固相法所得样品为纯净的Y2Cu2O5,具备较高的光催化产氢活性.用固相法制备的光催化剂Y2Cu2O5,当其用量为0.8 g/L、草酸为牺牲剂且初始浓度为0.05 mol/L时,表现出最佳光催化产氢活性,其产氢量为3.78mmol/(h.g).但Y2Cu2O5在草酸溶液中不稳定,会与草酸反应生成Y2(C2O4)32H2O,导致产氢活性降低.
展开▼
