Metal substitution in a Lindqvist polyoxometalate leads to improved photocatalytic performance.
Metal substitution in a Lindqvist polyoxometalate leads to improved photocatalytic performance.
复制标题
DOI：
10.1039/c2dt30304c
复制
发表时间：
2012-07
影响因子：
4
通讯作者：
J. Tucher;Yanlin Wu;Leanne C. Nye;Ivana Ivanović-Burmazović;Marat M. Khusniyarov;Carsten Streb
中科院分区：
文献类型：
--
作者：
J. Tucher;Yanlin Wu;Leanne C. Nye;Ivana Ivanović-Burmazović;Marat M. Khusniyarov;Carsten Streb
在一项对比研究中，对同金属和异金属钼酸基林德奎斯特多金属氧酸盐簇的光化学性质进行了研究，结果表明钒取代可作为一种简便的合成工具，用于优化簇的可见光吸收和光催化活性。单钒取代单元[VMo₅O₁₉]³⁻的光吸收可达480 nm，而钼酸类似物[Mo₆O₁₉]²⁻的光吸收主要在400 nm以下的紫外区域。利用含时密度泛函理论（TD - DFT）计算进一步研究了这两种簇的电子吸收性质，结果表明钒的引入导致了低能的O→V配体到金属的电荷转移（LMCT）跃迁的形成。在紫外和可见光照射下的对比光化学染料分解测试反应中，观察到[VMo₅O₁₉]³⁻具有更高的反应活性，其转化数超过1600。此外，研究表明在厌氧条件下，光反应比在有氧条件下进行得更快，这表明氧在其中一个光氧化还原步骤中起到了猝灭剂的作用。
The photochemical properties of homo- and heterometallic molybdate-based Lindqvist polyoxometalate clusters are investigated in a comparative study and it is shown that vanadium substitution can be used as a facile synthetic tool to optimize the visible light absorption and photocatalytic activity of the cluster. The mono-vanadium substituted unit, [VMo(5)O(19)](3-) shows light absorption up to 480 nm whereas the light absorption of the molybdate analogue [Mo(6)O(19)](2-) is mainly in the UV region below 400 nm. The electronic absorption properties of both clusters are further investigated using TD-DFT calculations which show that vanadium incorporation leads to the formation of low-energy O → V LMCT transitions. In comparative photochemical dye decomposition test reactions under UV and Vis irradiation, a higher reactivity is observed for [VMo(5)O(19)](3-) together with turnover numbers of more than 1600. In addition it is shown that under anaerobic conditions, the photoreaction proceeds faster than in the presence of oxygen, suggesting that oxygen acts as a quencher in one of the photoredox steps.