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  • 02월 28일 17시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

제123회 대한화학회 학술발표회, 총회 및 기기전시회 안내 Promoting water photooxidation on transparent WO3 thin films using metal oxide overlayers

2019년 2월 8일 00시 48분 16초
PHYS3-4 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
금 15시 : 40분
Physical Chemistry - Physical Chemistry Approaches in Energy and Environmental Materials
저자 및
Wooyul Kim
Department of Chemical and Biological Engineering, Sookmyung Women's University, Korea
Tungsten trioxide (WO3) is widely known as one of the most promising water photo-oxidation materials due to the visible range absorption. However, it has inherent limitation in the formation of peroxo species, stability and recombination of surface defect site. Nowadays it’s being gradually overcome by different methods, such as surface passivation, oxygen vacancy control and the chemically and physically deposition of co-catalysts. Here, WO3 (electrodeposited), Al2O3/WO3, and TiO2/WO3 (prepared by atomic layer deposition, ALD) electrodes were employed to investigate the role of the passivation overlayer by using both photoelectrochemical activity and laser flash photolysis measurements for charge carrier dynamic. It shows the different photoelectrochemical results based on passivation materials. In particular, femtosecond to microsecond transient absorption spectroscopy measurements of WO3, Al2O3/WO3, and TiO2/WO3 clearly showed that the ultra-fast pathway in the presence of the Al2O3 and TiO2 overlayer (ca. ps) under applied bias condition whereas the relatively long-trapped holes portion increased with overlayer (ca. s), facilitating water photooxidation. Moreover, we also carefully tuned oxygen vacancy of tungsten oxide form W to WO3 via WO2 using high temperature anodization method. Through the potassium contained non-aqueous anodization process, few amount of potassium can stabilize to oxygen vacancies in tungsten oxides. Various application of precise tuned tungsten oxide (e.g., both water oxidation and reduction process, oxygen reduction, etc) will be presented.