一步法合成Bi_(4) O_(5)Br_(x)I_(2-x)用于污染物高效光催化降解

One-pot synthesis of Bi_(4) O_(5)Br_(x)I_(2-x) for excellent photocatalytic degradation of pollutant

文中采用一步溶剂热法合成一系列不同Br/I比例的Bi_(4) O_(5)Br_(x)I_(2-x)光催化剂,通过XRD、场发射扫描电子显微镜、BET、紫外可见红外漫反射仪、PL、电化学等表征手段对样品进行分析。在可见光下降解苯酚作为探针实验,研究了其光催化性能。结果表明:Bi_(4)O_(5)Br_(1.2)I_(0.8)的降解效率最高,60 min的降解效率可达到94.6%,分别为Bi_(4)O_(5)Br_(2)和Bi_(4)O_(5)I_(2)的9.91和1.55倍;经过5个周期的循环实验,Bi_(4)O_(5)Br_(1.2)I_(0.8)光催化剂的稳定性保持良好,这种出色的光催化降解性能也广泛适用于其他无色持久性有机物。最后,对光降解污染物的机理进行了分析,催化活性的提高归因于富铋策略与固溶体的协同作用。这项工作为高活性环境修复型光催化剂的设计提供了思路。

A series of Bi_(4) O_(5)Br_(x)I_(2-x) with different ratio of bromine and iodine by a one-step solvothermal method was successfully constructed.The photocatalysts were characterized by XRD,FESEM,UV-vis DRS,BET,PL and electrochemistry measurement.The photocatalytic properties were evaluated with photodecomposition of phenol as probe experiment under visible-light irradiations.Bi_(4)O_(5)Br_(1.2)I_(0.8) has the highest degradation efficiency,and it can degrade 94.6%phenol within 60 min,which was 9.91 and 10.9 and 1.55 times greater than that of Bi_(4)O_(5)Br_(2) and Bi_(4)O_(5)I_(2),respectively.Recycling experiments reveal that Bi_(4)O_(5)Br_(1.2)I_(0.8) photocatalyst is reusable.This excellent photoactivity can expand to other colorless organic contaminants,too.Finally,the mechanism of photodegradation of polluts was analyzed.The enhanced activity can be ascribed to the synergistic effect of bismuth-rich and solid solution.This work can give ideas for the design of highly active photocatalysts toward environmental remediation.