由木屑萃取液製備奈米銀/二氧化鈦複合膜應用於光觸媒與pH感測器之研究

Preparation of Nanosized Ag/ TiO2 Composite Films from the Sawdust Extract for Photocatalyst and pH Sensor Applications

紀重仰(Chung- Yang Chi)

指導教授 ： 黃英邦

國立虎尾科技大學/工程學院/材料科學與綠色能源工程研究所/碩士(2013年)

https://doi.org/10.6827/NFU.2013.00107

摘要

本研究第一部分是以檜木與樟木之木屑為實驗材料，將木屑與5 N硫酸共同加熱3小時，將蒸餾冷凝出的萃取液以銀鏡反應定性分析萃取液是否含有糠醛。其次，將鈦片置於0.5M硫酸溶液中，以鈦片為陽極，白金為陰極，以15V定電壓及室溫下進行陽極處理30分鐘製備出二氧化鈦。然後將其置於糠醛萃取液和硝酸銀等混合液中，於溫度30~35℃下，反應時間分別為8及15分鐘以化學鍍之方式將銀鍍於二氧化鈦基材上，並以XRD分析其結構及掃描式電子顯微鏡(FE-SEM)觀察其表面型態。
第二部份是將鍍銀之二氧化鈦置於燃料電池模擬環境，即0.5M硫酸水溶液中，藉由動態極化實驗探討在0.5M硫酸水溶液中的腐蝕行為。實驗結果顯示，經化學鍍銀的二氧化鈦相較於純鈦基材，其腐蝕電位有朝貴電位移動及腐蝕電流密度下降之趨勢。
第三部份是將不同木屑萃取液無電鍍銀沉積的二氧化鈦分別置入10 ppm的酸性橙色7號染劑水溶液中，經400W的紫外光照射進行染劑降解之研究，照射時間為4小時，並以分光度計量測光照後之染劑濃度，其溶液濃度都有明顯的降低。
第四部份是將不同的銀二氧化鈦電極分別置入pH 2、4、7及10的標準液中，測試對不同氫離子濃度的電位感應性能，藉由數學模擬分析當pH=2及4時氫離子擴散係數為10-2~10-6次方，當pH=7及10時氫離子擴散係數為10-11次方，其感應靈敏度、響應時間及擴散係數均以15分鐘沉積的銀二氧化鈦電極具有較好的效果，由實驗結果顯示，本研究所製備具銀二氧化鈦電極適合應用於燃料電池雙極板、光觸媒與pH感測器上。

關鍵字

木屑萃取 ； 二氧化鈦 ； 陽極處理 ； 動態極化 ； 光觸媒 ； pH感測器

並列摘要

There are four parts in this study. Firstly, we report how to extract the furfural solution using 5N sulfuric acid (H2SO4) solution is obtained from the Chamaecyparis obtusa var. formosana and Cinnamomum camphora sawdust materials for the preparation of chemical plating silver on a titanium oxide film (TiO2), respectively. The qualitative analysis of furfural is used by silver mirror reaction. Titanium oxide film is manufactured by anodization in 0.5 M sulphuric acid solution, titanium foil as anode and platinum as cathode at room temperature under 15 V constant potential conditions. Titanium substrate anodized was placed in a mixed solutions at reaction time of the 8 and 15 minutes under the temperature of 30 ~ 35 ℃for the silver coating by the chemical plating, respectively. After the deposition, the Ag/TiO2 film is investigated by the XRD analysis and the surface morphology of Ag/TiO2 electrodes is observed by the FE-SEM.
Secondly, the corrosion behavior of the Ag/TiO2 film is investigated in a simulated polymer electrolyte membrane fuel cell (PEMFC) environment included 0.5 M H2SO4 solution at room temperature. Potentiodynamic polarization test is performed to determine the corrosion properties of chemical Ag plating. It was found that corrosion potential of the coated sample at room temperature was shift toward noble potential and corrosion current density decreased.
Thirdly, the photocatalytic degradation of dyeing agent for acid orange 7 (AO7) at 10 ppm concentrations by the Ag/TiO2 film were carried out under 400W UV radiation for 4h respectively. Spectrophotometer confirmed that concentration was greatly reduced.
Fourthly, use the prepared Ag/TiO2 electrodes under pH 2, 4, 7 and 10 standard solutions to test the potential sensing performance of different concentration of hydrogen ion, respectively. Through the mathematical analysis the hydrogen ion diffusion coefficient is determined. For pH 2 and 4 the hydrogen ion diffusion coefficients are 10-2~10-6 order. However, for pH 7 and 10 are 10-11 order. These results indicate that the prepared sensors have good response time and stable ability in the standard solutions. Experimental results show that the Ag/TiO2 electrode is suitable for PEMFC bipolar plate, Photocatalyst and pH sensor applications.

並列關鍵字

Sawdust extract ； Titanium oxide film ； Anodizing ； Potentiodynamic polarization test ； Photocatalyst ； pH sensor

參考文獻

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