Super-high activity of Bi3+ doped Ag3PO4 and enhanced photocatalytic mechanism
Super-high activity of Bi3+ doped Ag3PO4 and enhanced photocatalytic mechanism
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DOI：
10.1016/j.apcatb.2014.01.020
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发表时间：
2014-06
影响因子：
22.1
通讯作者：
Shuna Zhang;Shujuan Zhang;Limin Song
中科院分区：
文献类型：
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作者：
Shuna Zhang;Shujuan Zhang;Limin Song
采用离子交换法合成了Bi掺杂的Ag 3 PO 4，并对其结构和性能进行了系统的表征。Bi ~（3+）掺杂改变了Ag_3PO_4的晶格性质，降低了Ag_3PO_4的价带位置，加宽了Ag_3PO_4的禁带宽度。X射线衍射和X射线光电子能谱分析表明，掺杂的Bi 3+离子取代了P-O四面体中的P5+离子。橙子（MO）光催化降解实验表明，Bi掺杂量为2wt%的Ag 3 PO 4催化剂具有最高的活性，在1g/L的催化剂下，6 min后的降解率达到90.7%，而纯Ag 3 PO 4对MO的降解率仅为27.3%。其降解速率常数是未掺杂的Ag 3 PO 4的4.5倍。特别地，2wt% Bi掺杂的Ag 3 PO 4设法光降解高浓度（40 mg/L）MO（1 g/L催化剂），降解速率常数为未掺杂的Ag 3 PO 4的7.3倍。·OH自由基是Bi掺杂Ag 3 PO 4催化氧化MO的主要活性物种。Bi ~（3+）的掺杂显著减少了Ag_3PO_4表面的OH缺陷，提高了MO的降解效率。此外，密度泛函理论计算表明，Bi掺杂对Ag 3 PO 4电子结构的影响可能是其光催化性能增强的重要原因。
Bi-doped Ag3PO4was synthesized by an ion exchange method, and its structure and properties were characterized systematically. Doping Bi3+ions into the crystal lattice of Ag3PO4changed the properties of particles, reduced the valence band position and widened the band gap of Ag3PO4. The doped Bi3+ions have replaced P5+ions of P–O tetrahedrons according to the XRD and XPS analysis. The testing of methyl orange (MO) photodegradation showed that 2 wt% Bi-doped Ag3PO4had the highest activity, with the degradation rate reaching 90.7% after 6 min (1 g/L catalyst) when pure Ag3PO4degraded only 27.3% of MO. Its degradation rate constant was 4.5 times that of undoped Ag3PO4. Particularly, 2 wt% Bi-doped Ag3PO4managed to photodegrade high-concentration (40 mg/L) MO (1 g/L catalyst), with the degradation rate constant 7.3 times that of undoped Ag3PO4. •OH radicals were the main active species in the oxidation of MO over Bi-doped Ag3PO4. Doping Bi3+substantially reduced OH defects on the surface of Ag3PO4, which significantly increased the degradation efficiency of MO over Ag3PO4. In addition, the density-functional theory calculation revealed that the influence of Bi dopants on the electronic structure may be an important reason for the enhanced photocatalytic performance of Ag3PO4.