基於In2O3/Borophene複合材料之可撓性二氧化氮感測器的研製

Abstract

在這個AI快速發展的時代，自動駕駛、智慧工廠等需求不斷提升，其中為了接收現實環境資訊所使用的感測器成為了重要的一環。NO2為一種有毒氣體，其主要來自於化石燃料的燃燒，故容易累積於工業活動、交通繁忙地區和發電廠周圍。為了環境與人類的健康安全著想，開發一種具有高響應、高穩定性且能即時監控NO2濃度的氣體測器，已成為重要的議題。本研究選用對苯二甲酸(1,4-benzenedicarboxylic acid, H2BDC)以及硝酸銦水化合物(Indium nitrate hydrate, In(NO3)3·xH2O)作為製備In2O3的材料。接著，使用高壓均質法將高純度硼粉剝離成硼烯奈米片(Borophene nanosheets, BNs)。最後，將BNs與In2O3複合即可合成In2O3/Borophene氣體感測材料。調整In2O3/Borophene的複合參數後，進行一系列的材料特性分析，並比較不同比例之In2O3/Borophene材料對於NO2氣體的靈敏度。另外，使用CO2雷射在聚醯亞胺(Polymide, PI)薄膜表面製作石墨烯指叉電極，電極尺寸為14 mm × 10 mm，電極間距與電極線寬的尺寸皆為0.5 mm，將材料塗覆在指叉電極表面，即完成可撓式氣體感測器元件之開發。研究顯示，In2O3/BNs-2在室溫下對10 ppm NO2的響應高達2117.9%，比純In2O3 (1738.4%)提升了379.5%。此外，In2O3/BNs-2在室溫下針對不同濃度(0.25-100 ppm) NO2表現出優異的線性關係，並經過計算最低檢測極限(Limit of detection, LOD)為4.12 ppb，較純In2O3 (50.76)降低了91.9%。另外，經過一系列測試，In2O3/BNs-2展現出優異的再現性(Repeatability)、選擇性(Selectivity)以及長期穩定性(Long-term stability)。結果表明，In2O3/Borophene所產生的異質結接面(Heterojunction)以及豐富的空缺氧(Vacancy oxygen)，使得In2O3/Borophene展現出對NO2優異的感測性能，證明具有成為NO2感測材料的巨大潛力。In this era of rapid AI development, sensors used to gather real-world environmental data have become crucial. NO2, a toxic gas primarily emitted from fossil fuel combustion, accumulates in industrial areas, busy traffic zones, and around power plants. To ensure environmental and human health, developing a gas sensor capable of high responsiveness, stability, and real-time monitoring of NO2 concentration is crucial. In this study, 1,4-benzenedicarboxylic acid (H2BDC) and indium nitrate hydrate (In(NO3)3·xH2O) were used to synthesize In2O3 materials, while borophene nanosheets (BNs) were prepared by exfoliating high-purity boron powder via high-pressure homogenization. The In2O3 and BNs were then combined to fabricate In2O3/Borophene gas sensing materials. After adjusting the composite parameters, a series of material characterizations were conducted to evaluate the NO2 sensing performance of different In2O3/Borophene ratios. Additionally, CO2 laser processing was used to fabricate laser-induced graphene interdigitated electrode on polyimide (PI) film, with electrode dimensions of 14 mm × 10 mm and electrode spacing and line width of 0.5 mm. The sensing material was coated onto the electrode surface to create flexible gas sensor devices. The results showed that In2O3/BNs-2 achieved a high response of 2117.9% to 10 ppm NO2 at room temperature, representing a 379.5% improvement over pure In2O3 (1738.4%). It also exhibited excellent linearity across 0.25-100 ppm NO2 concentrations, with a low limit of detection (LOD) of 4.12 ppb, which is 91.9% lower than pure In2O3 (50.76 ppb). Furthermore, In2O3/BNs-2 demonstrated outstanding repeatability, selectivity, and long-term stability. The enhanced performance is attributed to the heterojunction interface and abundant oxygen vacancies in the In2O3/Borophene composite, confirming its strong potential as a NO2 sensing material.