Dmap ligand modified [CoW12O40]6- compound photocatalyzed degradation of salicylic acid

Abstract A novel compound based on [CoW12O40]6−, (Hdmap)6[CoW12O40]·3H2O (1) (dmap = N-(4-pyridyl)dimethylamine), has been hydrothermally synthesized and characterized by the elemental analysis, TG, IR, XRD and single crystal X-ray diffraction. Compound 1 compose of one [CoW12O40]6− polyoxoanion, six protonation of the dmap and three water molecules. Each [CoW12O40]6− polyoxoanion is connected to form three different one-dimensional structure(A, B C chains) by the hydrogen bond and π-π interaction further linked to ABAB plane. Interestingly, this ABAB plane constitutes a three-dimensional structure through hydrogen bond and π-π action links, in which there are [CoW12O40]6− anions in four different directions and each is linked horizontally by the organic ligands. Compound 1 showed excellent photocatalytic activities for the degradation of salicylic acid (97.45%). The comparative experiments demonstrate that compound 1 possesses higher activities in catalytic degradation of salicylic acid than that of three raw materials. As the catalyst dosage and the H2O2 increase, the degradation rate of the compound 1 increases, and the optimal catalyst dosage is 50 mg crystals and H2O2 dosage is 2 mL. In addition, compound 1 also exhibits high photocatalytic cycle stability and degradation rate is 92.13% after 5 cycles, which may be a potential catalyst in the photocatalytic degradation of salicylic acid design.