Keggin型铬取代杂多阴离子/D301R可见光催化性能

将Keggin型铬取代磷钨杂多阴离子PW11O39Cr(Ⅲ)(H2O)4-(PW11Cr)负载于弱碱性阴离子交换树脂D301R表面，制备了固体光催化剂PW11Cr/D301R,并以模型污染物罗丹明B(RhB)的降解为探针评估了该催化剂的可见光催化活性,讨论了光催化反应机理,同时考察了催化剂剂量、溶液pH值和溶液中常见离子对RhB可见光催化降解反应的影响以及催化剂的稳定性。 实验结果表明,当PW11Cr/D301R的剂量为100 mg时,10 μmol/L RhB水溶液暴露在200 W金卤灯下进行照射,RhB完全降解所需的时间仅为30 min,比PW11Cr均相体系缩短了3倍;反应180 min总有机碳(TOC)去除率约为84%。 催化剂剂量、溶液pH值和溶液中存在的Cl-、SO2-4和PO3-4对RhB光催化降解反应的速率均有一定影响。 催化剂循环实验显示经循环使用7次后催化剂的活性几乎没有损失。

Visible Light Catalysis of Keggin-type Cr-Substituted Heteropolyanion/D301R

A solid photocatalyst of Keggin-type Cr(Ⅲ) substituted heteropolytungstates immobilized on the surface of alkalescent anionic exchange resin D301R(PW11Cr/D301R) was prepared. Its visible light photocatalytic activity was assessed through the degradation of a model pollutant rhodamine B(RhB). The photocatalysis mechanism was discussed and influences of the PW11Cr/D301R dosage, the solution pH and the common anions existing in solution on the photocatalytic degradation rate of RhB were also examined. The time required to achieve a complete degradation of RhB is only 30 min in the presence of 100 mg PW11Cr/D301R when a solution containing 10 μmol/L RhB is exposed to irradiation of the 200 W metal halide lamp. This process is three times faster than that in the PW11Cr homogeneous system. Approximate 84% of the total organic carbon(TOC) removal is reached at 180 min. The PW11Cr/D301R dosage, the solution pH, and existing anion such as Cl-, SO2-4 or PO3-4 all have an obvious influence on the photocatalytic degradation rate of RhB. There is no obvious lost of photocatalytic activity of PW11Cr/D301R after seven repetitive uses.