水热合成条件对Bi_2WO_6可见光催化性能的影响

The effect of preparation conditions on the photocatalytic activity of Bi_2WO_6 under visible light

TiO2被广泛应用于光催化领域,但其只能在紫外光下响应,对太阳光利用率极低,因此开发能够吸收可见光的催化剂很有必要。以Bi(NO3)3.5H2O和Na2WO4.2H2O为原料,采用温和的水热法在不同温度、pH条件下制备了可见光响应的光催化剂Bi2WO6。通过XRD、DRS等技术对合成Bi2WO6进行表征。以氙灯为光源(λ>420nm),以罗丹明B(RhB)为模型污染物进行降解实验,探讨不同条件下合成的Bi2WO6的可见光光催化性能。实验结果表明,在140℃、pH=1条件下合成的Bi2WO6对RhB的降解效果最好,反应4h,脱色率达到97.7%。

TiO2 has been widely used in the photocatalystic process but can only display the photocatalytical activity in the ultraviolet region, leading to the low utilization rate of sunlight. It is necessary to put emphasis on searching new photocatalysts with visible light response. In this paper, Bi2WO6 was synthesized by the hydrothermal method with different temperature and pH using Bi（NO3）3·5H2O and Na2WO4·2H2O as raw materials. And the samples were characterized by XRD and DRS. A xenon lamp （λ〉420 nm） was used as an illuminant in the degeneration experiment and Rhodamine B（RhB） was chosen as the model substance to evaluate photocatalytic activity of Bi2 WO6. The results showed that the photocatalytic activity of the Bi2WO6 synthesized at 140℃, pH = 1 is the best, the degradation rate of RhB is 97.7% in 4 h.