La3+ 取代的纳米尺寸砷钨氧簇的合成、 晶体结构及光催化性质研究.

Based on the principle of molecular design and self-assembly, a novel rare earth based arsenotungstate was obtained by introducing rare earth LaⅢ ions into the lacunary polyoxotungstates clusters with vacancy structure by one-pot method with Na2 WO4 ·2H2 O, NaAsO2 and LaCl3 ·6H2 O as the main materials. The structure and composition of this complex was confirmed by single-crystal X-ray diffraction, X-ray powder diffraction (PXRD), infrared spectroscopy (IR) and so on. The single crystal X-ray diffraction results show that the complex is in the monoclinic system, C2/c space group, and with the cell parameters of a =3.595 56(14) nm, b =1.222 48(4) nm, c =2.247 34(9) nm, β = 117.117 0(10)°, V =8.792 3(6) nm3, Z =4. The molecular formula of this compound is [(CH3)2 NH2]8 H3. 56 [{LaO(H2 O)2 }{WO(H2 O)}{W0. 24 (H2 O)2 } {AsW9 O33 }2]. And the polyoxoanion [{LaO(H2 O)2 }{WO(H2 O)}{W0. 24 (H2 O)2 }{AsW9 O33 }2]11. 56 - shows a novel sandwich type structure, which can be simply described as two trilacunary Keggin type{AsW9 O33 } units are linked by a {LaO(H2 O)2 } segment, a {WO(H2 O)} segment and a {W0. 24 (H2 O)2 } segment. Catalytic degradation property of this compound for Rhodamine-B was further inverstigated. The results demonstrate that the compound shows good photocatalytic activity under the condition of 300 W Hg lamp irradiation, and the degradation efficiency reaches to 74%. [ABSTRACT FROM AUTHOR]