水熱法合成之Na(BixTa1-x)O3光觸媒在可見光照射下進行水裂解產氫

本研究使用NaOH、Ta2O5和NaBiO3當作前驅物，經由不同比例的混合後藉由水熱法(Hydrothermal method)製備Na(BixTa1-x)O3光觸媒，並且使用含浸法負載共觸媒NiO以增加光觸媒活性。製備得到的光觸媒利用X光繞射分析儀(XRD)、紫外光-可見光光譜分析儀(UV-Vis)、能量散佈光譜儀(EDS)、掃描式電子顯微鏡(SEM)來分析光觸媒的特性。由XRD結果得知，在氫氧化鈉濃度14M以及製備溫度240℃時Na(Bi0.08Ta0.92)O3光觸媒有最佳的晶體結構，且當Na(BixTa1-x)O3光觸媒的x值越大時其繞射峰角度越往大角度偏移。由UV-Vis可得知Ta2O5和NaBiO3的比例不同時，會造成臨界波長的位移，隨著NaBiO3的含量增加會造成臨界波長的紅平移，且x=0.08時有最大的臨界波長約為422nm，enery gap約2.93 eV。由EDS鑑定結果得知光觸媒成份確為Na(BixTa1-x)O3。由SEM結果得知光觸媒顆粒為平滑的立方體，隨著氫氧化鈉濃度、製備溫度及NaBiO3的含量的不同，粒徑大小也會隨著改變。由實驗結果得知在氫氧化鈉濃度14M、製備溫度240℃時Na(Bi0.08Ta0.92)O3光觸媒具有最好的反應活性，產氫速率達64.55 μmole/h，當負載0.1wt% NiO共觸媒時產氫速率可達82.48 μmole/h。

關鍵字

氫氣；水熱法；光觸媒；水裂解； Na(BixTa1-x)O3

並列摘要

In this research,NaOH,Ta2O5 and NaBiO3 are used as precursors,through their mixing in various proportions,then Hydrothermal Method is utilized to prepare the photocatalyst Na(BixTa1-x)O3,and the impregnation method is used to load the co-catalyst NiO to increase the activity of the photocatalyst.The characteristic properties of the photocatalysts prepared are analyzed respectively by means of X-ray diffraction analyzer (XRD), Ultraviolet-visible light diffuse spectrometry analyzer (UV-vis), Energy Dispersed Spectrometer (EDS),and Scanning Electron Microscope (SEM).From the results of XRD, it is known that as the NaOH concentration reaches to 14M and at the preparation temperature of 240℃,the photocatalyst Na(Bi0.08Ta0.92)O3 possesses the best crystalline structure,and that as the x-value of the photocatalyst Na(Bi0.08Ta0.92)O3 becomes larger,its diffraction peak angle tends more to shift to large angle.From the UV-vis,we know that as the proportion of Ta2O5 and that of NaBiO3 are different,the shift of the critical wave length is caused to happen,following the increase of the content of NaBiO3,it would cause the red shift of the critical wave length to occur,besides,as x=0.08,the maximum critical wave length is about 422nm,and the energy gap is about 2.93eV.From the identification results of EDS,it is known that the composition of the photocatalyst is confirmed to be Na(BixTa1-x)O3.From SEM results,we know that the grain particles of the photocatalysts are smooth cubes,and the particle diameter sizes vary with the NaOH concentration,the preparation temperature and the NaBiO3 content.From the experimental results,it is known that when the NaOH concentration is 14M,the preparation temperature is 240℃,the photocatalyst Na(Bi0.08Ta0.92)O3 possesses the best reaction activity,the hydrogen producing rate reaches to 64.55 μmole/h.In addition,as the photocatalyst is loaded with co-catalyst NiO of 0.1wt%,the hydrogen producing rate can reach to 82.48 μmole/h.

並列關鍵字

Na(BixTa1-x)O3 ； hydrogen ； Hydrothermal method ； photocatalyst ； water-splitting

參考文獻

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國際替代計量

水熱法合成之Na(BixTa1-x)O3光觸媒在可見光照射下進行水裂解產氫

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