複合式光觸媒之製備與分析

Synthesis and Characterization of Composite Photocatalyst

徐金正(Chin-Cheng Hsu)

指導教授 ： 吳乃立

國立臺灣大學/工學院/化學工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.00503

摘要

利用水熱法製程在120 ~ 180 ℃的溫度範圍之間以過氧化鋅為前驅物來製備氧化鋅/過氧化鋅的複合材料。氧化鋅/過氧化鋅複合材料所呈現出的形態為在稜柱形氧化鋅結晶體的表面上有小顆粒狀的過氧化鋅「融合」在其上。此外，以溶膠-凝膠法以及初濕含浸法，利用二氧化鈦作為母相，並在不同鍛燒溫度下來製備鈦酸鍶/二氧化鈦之複合材料。另一方面，在光觸媒活性分析上，以波長300 nm的光源照射甲基橙以及亞甲基藍溶液以進行降解反應，發現氧化鋅/過氧化鋅與鈦酸鍶/二氧化鈦複合材料有最佳的光反應活性。如此反應活性的提高是由於在組成複合材料的兩相在表面存在著緊密鍵結的異相結構鍵結且兩種不同相的氧化物之間其結構上以及其能帶上的差異，因而有助於光激發電子電洞對的分離。
本研究同時也提出一種製備緊密接合雙成份半導體光觸媒組合物的製程，該製程是以該組合物內之其中一成份半導體光觸媒相為起始相，經由一個以上的化學反應將此起始相部份轉化合成出具不同化學組成之另一成份半導體光觸媒相，以形成最終之雙成份組合物物件以該製程所獲得之雙成份半導體光觸媒呈現較其任一組成的單一相材料有著更佳的光觸媒活性。

關鍵字

光觸媒 ； 複合材料 ； 氧化鋅 ； 過氧化鋅 ； 二氧化鈦 ； 鈦酸鍶

並列摘要

ZnO/ZnO2 composite photocatalysts were synthesized by hydrothermal treatment at 120 ~ 180 ℃ of ZnO2, which in turn was obtained from an aqueous solution of ZnSO4 and H2O2. The composite particles showed morphology of ZnO prismatic crystallites with small ZnO2 granules “fused” at surface. Besides, SrTiO3/TiO2 composite photocatalysts were prepared by sol-gel and incipient wetness impregnation method and proceeded to calcine at high temperature, with TiO2 as the main phase of the composite.
Photocatalytic activity was characterized based on photocatalytic degradation of methyl orange and methylene blue under UV-light (300 nm) illumination, and the maximum activity was both observed for the composite photocatalysts synthesized based on pre-formed main phase, ZnO/ZnO2 and SrTiO3/TiO2. The enhanced activity has been attributed to the presence of the intimate hetero-structure on the surface of composites and the effective way for the separation of excitons. This study also points out a new approach to synthesize a coupled composite photocatalyst containing strongly coupled constituents by phase transformation among the constituents through one or more than one chemical reaction(s).

並列關鍵字

Photocatalyst ； Composite ； ZnO ； ZnO2 ； TiO2 ； SrTiO3

參考文獻

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