کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6454865 | 1418818 | 2017 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Research PaperIdentification of homogeneous [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â as an effective molecular-light-driven water oxidation catalyst Research PaperIdentification of homogeneous [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â as an effective molecular-light-driven water oxidation catalyst](/preview/png/6454865.png)
- [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â exhibited high photocatalytic oxygen evolution with a high TON of 661.5.
- [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â maintained its structural integrity under the given photocatalytic conditions.
- [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â was stable during water oxidation.
- The CAdSV and THpANO3/toluene extraction were used to quantify the released amount of cobalt species.
- [Co4(H2O)4(HPMIDA)2(PMIDA)2]6â neither releases free Co2+ ions nor hydrolyzes into cobalt oxide or hydroxide.
Transition-metal complexes, especially cobalt complexes, are used as precatalysts in homogeneous water oxidation catalysis. However, a practical method of identifying the effective active species in cobalt-complex homogeneous catalysts under highly oxidizing conditions have not yet been established. In this work, (H3O)6·[Co4(H2O)4(HPMIDA)2(PMIDA)2]·2H2O (1) was introduced, and its photocatalytic performance was evaluated. The compound exhibited effective water oxidation catalysis, with a turnover number of 661.5 at pH 9.0 using [Ru(bpy)3](ClO4)2 as photosensitizers and sodium persulfate as sacrificial electron acceptor. Accordingly, 1 was used as target catalysts, and the active species was thoroughly investigated under catalytic conditions. The stability of 1 was further tested and confirmed by a series of experiments (cyclic voltammetry (CV), ultraviolet-visible (UV-vis) spectrometry, dynamic light-scattering (DLS), aging experiments, and extraction techniques). Results showed that 1 maintained its structural integrity under the given photocatalytic conditions. Furthermore, cathodic adsorptive stripping voltammetry and inductively coupled plasma-mass spectrometry were used to quantify the amount of Co2+ ions released from 1 into borate buffer after oxidation. The pH dependence of the oxygen-evolution performance of 1 and other cobalt species were then compared. Data collectively revealed that 1 was stable during water oxidation; it did not release free Co2+ ions and was not hydrolyzed to cobalt oxide or hydroxide, thereby confirming that 1 was the effective active species in water-oxidation catalysis.
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Journal: Applied Catalysis B: Environmental - Volume 202, March 2017, Pages 397-403