Summary: | 碩士 === 國立高雄科技大學 === 微電子工程系 === 107 === In this study, NaTaO3 photocatalyst materials were prepared by hydrothermal method. Hydrothermal synthesis was carried out at 200 °C using NaOH and Ta2O5 as precursors for 1, 2, 3, 4, 8 and 12 h, and labeled as 1H, 2H, 3H, 4H, 8H, and 12H, respectively. XRD and SEM were used to characterize structure and morphology of samples. Humidity and organic-dye-degradation properties of these materials were also analyzed in this work.
By changing the parameters of the synthesis time, it is found that the particles become larger as the synthesis time increases. From XRD structural analysis the prepared NaTaO3 samples have the orthorhombic structure. The residual Ta2O5 is obvious in sample(for a shorter synthesis time). When the synthesis time increases, it is found that the residual Ta2O5 is obviously decreased.
The organic-dye-degradation characteristic of sample 4H for 5 hours using UV lamp can reach 99%, and using white LED light it can still reach 95%. The sample 8H and 12H with thicker shell of NaTaO3 were found to have lower degradation rates.
Humidity devices were made by pasted the NaTaO3 powder on interdigitated electrodes. The sensing element of sample 4H reveals a good response time of 5s and recovery time of 16s at 95% humidity. In this work, the sample 4H has better photocatalytic and humidity sensing effects.
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