可见光驱动溴化银/溴氧化铋复合纳米 材料制备及活性评价*

室温沉淀法合成溴氧化铋（BiOBr）纳米片，然后通过离子交换法制备溴化银/溴氧化铋（AgBr/BiOBr）复合纳米材料，采用X射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）及紫外可见分光光度计（UV-Vis）对其进行表征，并进行了光催化降解实验。以节能、绿色的LED灯为可见光光源，AgBr/BiOBr复合材料光催化降解罗丹明B（RhB）和甲基橙（MO）的效率均高于BiOBr。AgBr/BiOBr降解RhB的活性强于MO。在AgBr/BiOBr光催化系统中，超氧自由基和空穴是主要的活性物种。不同pH条件下，AgBr/BiOBr对RhB均表现出理想的光催化降解效果，酸性条件下降解效率最佳；碱性环境下AgBr/BiOBr光催化降解MO的活性最高。经过循环利用，AgBr/BiOBr可见光催化活性呈现出一定程度的降低，归因于降解过程中产生了金属银。

Synthesis and activity evaluation of visible-light-driven AgBr/BiOBr composite nanomaterial

BiOBr nanosheets were synthesized by precipitation method at room temperature，and then the AgBr/BiOBr composite nanomaterial was obtained via an ion-exchange route.XRD，FESEM，and UV·Vis were employed to characterize the as-prepared materials.An energy-efficient and green LED lamp was used as visible light source.AgBr/BiOBr composite material showed a higher photocatalytic rate than pure BiOBr for RhB and MO degradation.The AgBr/BiOBr photocatalyst degraded RhB easier than MO.In the AgBr/BiOBr photocatalytic system，O2·- and h+ were considered to be the main active species.At the different pH conditions，AgBr/BiOBr exhibited an ideal photocatalyic activity for RhB degradation，and the highest photodegradation rate was found in the acidic condition.In the basic solution，AgBr/BiOBr showed the highest photocatalytic performance for MO degradation.The photocatalytic activity of AgBr/BiOBr decreased to different degrees after cycling runs due to the production of metallic silver in the photocatalytic process.