Issue
HWAHAK KONGHAK,
Vol.34, No.5, 543-547, 1996
세슘이 담지된 반도체 광촉매에서 물의 광분해 반응에 의한 수소의 생성
Hydrogen Evolution from Photocatalytic Decomposition of Water over Cesium Loaded Semicon- ductor Photocatalysts
세슘이 담지된 반도체 금속산화물 및 알칼리 금속을 결합시킨 반도체 금속산화물에 세슘이 담지된 광촉매에 의한 물의 광분해 반응을 수소 생성의 견지에서 관찰하였다. 이 광분해 반응에서 알코올의 첨가효과에 대하여 검토하였고 광반응 경로도 설명하고자 하였다. 세슘이 담지된 금속화합물 광촉매에서는 수소생성률이 그리 높지 않았다. 반도체 금속산화물에 알칼리 금속을 결합시키고 세슘을 담지시킨 금속화합물 광촉매의 경우, 수소 생성률이 크게 증가하였다. 이것은 이 금속화합물 광촉매의 광감응도가 알칼리 메탈의 영향으로 향상된 탓이라고 생각되었다. 니켈을 담지시킨 광촉매에서는 촉매를 환원-산화시킴으로서 그 촉매활성이
Hydrogen evolution from photocatalytic decomposition of water was studied on cesium loaded metal oxide and alkali treated metal compound photocatalysts. The effect of alcohol in photocatalytic decomposition of water was investiga- ted and the and path of photoreaction was schemingly explained. The rate of hydrogen evolution was not very high in case of cesium loaded metal oxide photocatalysts. In case of cesium loaded metal compound photocatalysts (trea- ing with alkali metal), it was more increased then the case of cesium loaded metal oxide. It was considered that cesium loaded metal compound photoca- talysts were given the enhancement of photoresponsibility. The photocatalytic activity of nickel-metal compound photocatalyst was highly improved by reduction-oxidation pretreatment, but that of cesium case was independent on the pretreatment. The reason is surmised that cesium has a strong oxidation ability into superoxide even in air. In the photocatalytic decomposition of alcohol-water mixture, the rate of hydrogen evolution was abruptly increased. Peculiarly, oxygen product was not detected, because the oxidation reaction of alcohol occurred simultaneously during the photoreaction.
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