- 學位論文
偵測硫化氫氣體的奈米結構之二氧化錫/金感測器
Nano-Structured SnO2-Au Sensor for H2S Detection
摘要
本研究目的是要利用二氧化錫/金之奈米結構複合材料發展一微型硫化氫氣體感測器。對於二氧化錫材料的製備，係以溶膠-凝膠法進行製備，並在其中摻入不同比例的奈米金膠體溶液，藉由旋轉塗佈法在指狀電極上形成薄膜，其煅燒溫度為400℃使之形成孔洞的結構，接著比較未摻入與摻入不同比例之奈米金之二氧化錫薄膜對於硫化氫氣體靈敏度之影響。藉由X光繞射分析、掃描式電子顯微鏡與穿透式電子顯微鏡來分析所製備出的二氧化錫與二氧化錫/金材料，探討其材料的表面型態、顆粒大小與是否符合二氧化錫結構和性質。結果顯示，在硫化氫氣體的偵測上發現有摻入奈米金微粒的二氧化錫/金薄膜，以SnO2+1Au的奈米複合材料對於硫化氫氣體的靈敏度最佳，並可於室溫下偵測到極限濃度為0.2 ppm。另外對於感測器的選擇性而言，在偵測20 ppm的二氧化硫、50 ppm的氨氣、1000 ppm的二氧化碳與20%的氧氣偵測中，其響應值都明顯低於偵測1 ppm的硫化氫氣體響應值。接著針對酒精干擾的偵測中，對於濃度為70%與99.5%的酒精氣體進行偵測，結果發現濃度為70%的酒精氣體會影響其偵測結果，但對於濃度為99.5%的酒精是較無影響。最後進行濕度干擾的偵測中，在50%、70%與80% RH的環境下進行偵測，結果顯示溼度較高的環境對於感測器是有一定程度的影響，所以對於溼度的問題仍需要去避免與克服。
並列摘要
The purpose of this study use nanostructured SnO2/Au to develop a miniature hydrogen sulfide gas sensor. We used the sol-gel method to synthesis SnO2 which doped with and without Au nanoparticles. Moreover, this developed sensing material was dripped on interdigital electrode by spin-coating method. These semifinished material sensors were calcine at 400℃ to form a porous structure. Compare with pure and Au doped SnO2 sensitivity for hydrogen sulfide detection. In charactering of sensing thin film, X-ray diffraction were used to analyze the composition of SnO2/Au nanocomposites. SEM and TEM images were respectively used to observer the morphology and to quantify the particle size. The result showed that for hydrogen sulfide detection, there have maximum response in SnO2+1Au composites, and was able to detect low concentration was about 0.2 ppm at room temperature. The selectivity of sensors for 1ppm H2S have maximum response and all sensors exhibited low response to 20 ppm SO2, 50 ppm NH3, 1000 ppm CO2 and 20% O2. Then we detect 70% and 99.5% alcohol vapor, the result revealed lower influence with 99.5% alcohol vapor than 70% alcohol vapor. We also studied the effect of humidity (50%, 70% and 80% RH) to H2S detection. The result show influenced with humidity. However, in humid environment have influence of sensor detection, so we need to avoid this condition.