2016 Fiscal Year Research-status Report
Photo-electrochemical water-splitting on conducting polymer composite materials
| Project/Area Number |
16K05922
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| Research Institution | Waseda University |
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Principal Investigator |
ウィンザージェンセン B 早稲田大学, 理工学術院, 教授(任期付) (70770410)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | Water splitting / Conducting polymers / Hydrogen / Electrochemistry |
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| Outline of Annual Research Achievements |
At the initiation of the project it was found that the use of iron(III) as oxidants for the polymerization of polythiophenes produced unwanted iron-oxide residuals and that these species work as electron traps during the light enhanced water-splitting, thereby limiting the H2 production. I2 was identified as ideal replacement oxidant for polyterthiophene (I2-PTTh) with H2 evolution of 330 mmol h-1 g-1.Surprisingly it was found that the catalytic activity for the I2-PTTh did not follow the expected Nernstian dependency of pH as previous seen for materials polymerized with iron(III). Instead an increase in onset potential was observed when moving to higher pH, which make I2-PTTh an ideal match for oxygen evolution electrodes like MnOx. Derivatives of terthiophene with phenyl or phenoxy groups has been successfully synthesized and the polymerization optimization and testing of these are ongoing.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The work related to the adoption of I2 as oxidant for the polymerization of ter-thiophene and derivatives thereof was not foreseen in the original plan. However, this shift has focused the synthesis activities to a much narrower range of possible thiophene-derivatives by providing an “universal” metal-free polymerization platform for the ter-thiophene motive. It is expected that this new knowledge and approach will accelerate the selection and testing of thiophene derivatives and thus make up for the delay in the synthesis of precursors.
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| Strategy for Future Research Activity |
The 2nd year will mainly concern the performance of PTTh derivatives with tuned HOMO levels to increase the reduction potential and thus achieve water-reduction at higher potentials. The focus will be on synthesizing and testing TTh derivatives where increasing the oxidation potential is combined with incorporation of hydrophilic entities such as -O-R or extended glycolic structures -O-(C2H4O)x-R and thereby obtain materials that fulfill both the requirements described in the research proposal. Incorporation of redox polymers. Selecting and testing redox polymers for the water-oxidation reaction. First choice will be from the group of materials with phenol/quinone functionality, where the redox potential fits the oxidation potential of water in similar fashion to how tyrosine is employed in biological systems.There are not intended any strategical changes of the research plans for the and 3rd year of the project.
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| Causes of Carryover |
For use as a reagent next year.
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| Expenditure Plan for Carryover Budget |
We will devote it to reagents next year.
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