- 學位論文
光激發鐵氮共摻雜氧化鈦高靈敏濕度氣體感測器
Highly Sensitive Photo-activated Sensors Based on Iron, Nitrogen Co-modified Peroxo Titanic Thin Film for Gas and Humidity Sensing
摘要
氣體感測器可以利用於有機氣體感測以及濕度感測上。有機氣體感測可以應用在醫學領域而濕度感測則廣泛應用於各種生活相關領域中。本研究開發了一種高靈敏性的溼度感測器並且可以偵測有機氣體。我們利用溶膠凝膠法合成任意比例的鐵氮共摻雜氧化鈦，並利用旋塗機旋塗在指叉狀金電極上，封裝在8 PIN 的 IC 腳座上，利用氣體產生系統量測對於水氣以及有機氣體的反應。 本氣體感測器對於水氣有極佳的感測效能，在不同頻率下對於水氣的阻抗值變化有極大的差異，用阻抗分析儀量測阻抗變化時在頻率為100 Hz時在相對溼度11-75%的變化可以達到近乎五個數量級的反應，並且在中低濕度時阻抗量測的反應呈現線性變化，中高濕度時電容量測的反應呈現線性變化。 在有機氣體方面本感測器可以有效偵測到甲苯以及甲醇在6000-10000ppm的濃度變化，我們利用紫外光對感測器進行照射15分鐘後，證明感測器在光激發後對於甲醇以及甲苯有良好的增益，並且本感測器對於甲醇以及乙醇有良好的分辨性。 本感測器在水氣的反應時間以及回復時間的表現上擁有小於兩秒的表現，在針對有機性氣體上則大約為20秒。推測因本研究材料表面親水，與氣體中水分結合後，有機氣體需和水分子搶結合位置，因此反應時間較慢。
並列摘要
Gas sensors can be utilized to detect volatile organic compounds (VOCs) or humidity. Volatile organic compound sensors and humidity sensors can be applied in many fields. In this research, we synthesized a new material consisting of iron and nitrogen co-modified peroxo titanium oxide, for the VOCs and humidity sensing applications. We developed a sol-gel technology to synthesize iron, nitrogen co-modified peroxo titanium oxide and the ratio of iron, nitrogen and titanium can be adjuted. UV light was used to improve the sensing performance of humidity and VOCs. This sensor has great response to humidity and the impedance value varies a lot with different frequencies. When using a impedance analyzer to measure the impedance change, the impedance change spanned almost five orders of magnitude during the measurement of relative humidity (RH) from 11%-75% under 100Hz. On the other hand, the sensor can measure the methanol and toluene from 6000 to 10000 ppm. We proved that our sensors have good improvements after illuminating 365nm ultraviolet light for 15 minutes. Our sensors have good selectivity between methanol and ethanol . Our sensors’ response time and recovery time are less than 2s to water, and approximately 20s to VOCs. Because the material surface is hydrophilic so water molecules can easily be adsorbed. It is believed that VOCs have to compete to the water molecules for reaction sites and thus the response time is slower than water.