氮掺杂Bi_2O_3光催化剂可见光催化降解2,4-二氯酚

Photocatalytic Degradation of 2,4-Dichlorophenol under Visible-light Irradiation Using Nitrogen-doped Bi_2O_3 Photocatalyst

采用自制的Bi2O3及氮掺杂Bi2O3(N-Bi2O3)光催化剂,以卤钨灯为光源,在可见光下对2,4-二氯酚进行光催化降解。结果表明,N-Bi2O3较Bi2O3具有更高的可见光催化活性。当N-Bi2O3光催化剂投加量为2.0 g/L、2,4-二氯酚初始浓度为20 mg/L和pH=7时,光催化反应320 min,2,4-二氯酚的降解率最高可达到91.5%。2,4-二氯酚的光催化反应初活性与其浓度之间的关系符合Langmuir-Hinshelwood动力学速率模型。对降解过程中总有机碳及Cl-测试结果表明,N-Bi2O3光催化剂能较好地完成对2,4-二氯酚的深度矿化及脱氯。

The photocatalytic degradation of 2,4-dichlorophenol was carried out using un-doped and nitrogen-doped bismuth oxide as catalysts under visible-light irradiation. The results indicated that the nitrogen-doped bismuth oxide exhibited a higher photocatalytic activity than that of the un-doped bismuth oxide. When 2.0 g/L of nitrogen-doped bismuth oxide was added to 20 mg/L of 2,4-dichlorophenol aqueous solution with initial pH=7, the degradation rate could reach 91.5%. Moreover, the relationship between 2,4-dichlorophenol degradation rate and its initial concentration follows the Langmuir-Hinshelwood model. The variations of total organic carbon and Cl- were also inspected during the photocatalytic reaction. It is suggested that it is beneficial for the mineralization and dechlorination for 2,4-dichlorophenol by using nitrogen-doped bismuth oxide as photocatalyst.