WO_3/BiOBr复合催化剂的制备及可见光催化降解甲基橙

以Bi(NO_3)5·5H_2O、Na Br、H_2WO_4为原料,采用一步水热合成法合成不同n(W)∶n(Br)的WO_3/BiOBr复合催化剂,并通过SEM和TEM对催化剂进行表征分析。以甲基橙为探针污染物,考察前驱液pH、水热温度、水热时间和n(W)∶n(Br)对WO_3/BiOBr复合催化剂活性的影响。结果表明,在pH为10.2、100℃水热时间6 h合成n(W)∶n(Br)为0.02的WO_3/BiOBr复合催化剂活性最好,光照120 min后,对目标污染物的降解率达99.39%,较BiOBr催化剂(合成条件为原始pH值,100℃水热反应6 h)提高了30.85%。采用水热合成法制备的WO_3/BiOBr复合催化剂具有良好的可见光活性。

Preparation ofWO3/BiOBr photocatalysts and their photocatalytic degradation of methyl orange under visible light

Using Bi(NO₃)₅·5H₂O、NaBr and H₂WO₄ as the raw materials,the visible-light photocatalyst WO₃/BiOBr of different n(W)∶n(Br) was synthesized by hydrothermal process.The as-prepared photocatalysts were characterized by SEM and TEM.The influerence of precursor solution pH,hydrothermal synthetic temperatures and time on catalytic activity of WO₃/BiOBr photocatalysts was investigated by using methyl orange dye wastewater as probe pollutant.The results showed that WO₃/BiOBr photocatalysts possessed the best photocatalytic activity under the preparation condition of precursor solution pH 10.2,hydrothermal syntheic temperature 100 ℃,hydrothermal synthetic time 6 h and W/Br molar ratio 0.02.After visible-light illumination for 120min,methyl orange degradation conversionover WO₃/BiOBrphotocatalysts was 99.39%,which was 30.85% higher than BiOBr prepared under the condition of original PH and 100 ℃ hydrothermal reaction for 24 h.Therefore,WO₃/BiOBr synthesised by hydrothermal method exhibited excellent photocatalytic activity under visible light irradiation.