Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
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Research Abstract |
Effects of spray conditions and heat-treatment on the photoelectrochemical behavior of TiO_2-oxide system coatings produced by plasma spraying were investigated. It is shown that the photocurrent of air plasma-sprayed coatings is larger than one of LPC plasma-sprayed coatings, and auxiliary gas, H_2, influences greatly the photoelectrolysis of TiO_2 and TiO_2-oxide mixture coatings. The photocurrent of TiO_2 plasma-sprayed coatings increases by adding various metal-oxides, such as Al_2O_3, Y_2O_3 etc, to TiO_2 coatings. The photoelectrochemical properties of TiO_2 and TiO_2-oxide system plasma-sprayed coatings are improved greatly by heat-treatment (400゚C,90min.) in air. The photocurrent of TiO_2 and TiO_2-oxides coatings that plasma- sprayed with plasma gas, Ar-H_2 and then heat-treated(400゚C,90 min.) in air, depend on the formation free energy of the additional oxide. And, photocurrents of such TiO_2-oxide mixture plasma- sprayed coatings increase with the decrease of the ionized donor density concentration, ND of TiO_2-oxide mixture photoanodes. It is concluded that polycrystalline TiO_2 coatings produced by the plasma-spraying display similar photoelectrochemical characteristics to single-crystal TiO_2 material.
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