本研究首先以史托博法(Stöber method)製備的非晶SiO₂球當作模板，其直徑約133 nm；再將TiO2披覆在表面，形成SiO₂@TiO₂核殼結構複合物。所得到的複合物與2.5 M之氫氧化鈉(NaOH)溶液反應不同時間，改變其形貌。SEM結果發現，隨反應時間由3分鐘增長為25分鐘，複合物的形貌由含有矽球之蛋黃殼結構，轉變為空心球，最後成為碗狀結構。BET結果顯示碗狀結構的樣品，其孔洞直徑及表面積分別為73.5 nm及192 m2g−1。不同形貌的樣品於500°C下進行退火後，結構分析顯示，隨反應時間增長，樣品的缺陷含量增加，能隙值下降，光降解效能提高。其中，反應25分鐘的樣品(碗狀結構)在紫外光照射下，可於12分鐘內將溶液中的甲基橙完全降解。將退火溫度提升至800°C後，所有樣品的形貌不變，但結晶性改善，光降解效率也進一步提高。碗狀結構之樣品能夠在紫外光照射下，於8分鐘內將溶液中的甲基橙完全降解。

In this study, amorphous SiO2 spheres prepared by the Stöber method were used as templates with a diameter of about 133 nm; then TiO2 was coated on the surface to form a SiO2@TiO2 core-shell composite. The composite morphology was adjusted by tuning the reaction time with a 2.5 M sodium hydroxide (NaOH) solution. With increasing the reaction time from 3 to 25 minutes, the composite morphology changed from egg yolk-shell structure containing silicon spheres to hollow spheres and finally into a bowl-shaped structure. The BET results show that the bowl-shaped sample has a pore diameter and surface area of 73.5 nm and 192 m2g−1, respectively. After the samples with different morphologies were annealed at 500°C, the structural analysis showed that with the increase in the reaction time, the defect content of the samples increased, the energy gap value decreased, and the photodegradation efficiency increased. Among them, the sample reacted for 25 minutes (bowl-shaped structure) can completely degrade the methyl orange in the solution within 12 minutes under ultraviolet light irradiation. After increasing the annealing temperature to 800°C, the morphology of all samples remained unchanged, but the crystallinity was improved, and the photodegradation efficiency was further enhanced. The bowl-shaped sample can completely degrade the methyl orange in the solution within 8 minutes under ultraviolet light irradiation.

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