溴化银/碳酸银复合光催化剂的制备及其光催化性能研究

Preparation and property of AgBr/Ag_(2)CO_(3) composite photocatalyst

以十六烷基三甲基溴化铵(CTAB)为溴源,采用简单的一步共沉淀法合成AgBr/Ag_(2)CO_(3)复合光催化剂,并利用粉末衍射(XRD)、扫描电镜(SEM)、紫外漫反射(UV-Vis DRS)、荧光光谱(PL)和紫外可见光分光光度计等进行表征。以亚甲基蓝溶液为模拟染料进行光催化降解实验,探讨了反应时间、复合物质量比对样品催化性能的影响。结果表明:AgBr的光生电子易迁移到Ag_(2)CO_(3)表面,使复合催化剂稳定性增强,表现出比单一AgBr或Ag_(2)CO_(3)更优越的光催化性能。共沉淀反应时间为1h,加入0.3g CTAB合成的AgBr/Ag_(2)CO_(3)样品在用量为0.08g时降解200mL 10mg/L亚甲基蓝溶液30min后,降解率达到99.19%,第3次循环降解,其降解率仍高达60.91%,循环利用率高。

AgBr/Ag_(2)CO_(3)composite as photocatalyst was synthesized via a facile one-step coprecipitation method by adding different contents of CTAB as Br source,and characterized by XRD,SEM,UV-Vis DRS and PL.The photocatalytic activity of the as-synthesized AgBr/Ag_(2)CO_(3)composite were explored by the removal of the photocatalytic degradation of methylene blue(MB)aqueous solution under illumination of visible-light.The effects of coprecipitation time and quality added of CTAB on the catalytic performance of the samples were also investigated.The results revealed that AgBr/Ag_(2)CO_(3)composite shown a superior photocatalytic behavior than those of the single-phase AgBr or Ag_(2)CO_(3)due to the photo-produced e-of AgBr may be transferred into Ag_(2)CO_(3).Among these composites,0.08g AgBr/Ag_(2)CO_(3)composite obtained with 0.3g CTAB,and co-precipitation time of 1h,shown the highest degradation rate with 99.19%removal efficiency of MB within 30min.More importantly,the recycling tests proved that the degradation rate of methylene blue can reached 60.91%after cycled for three times.