Ryou Heejoong, Kim Sunjae, Shin Myunghun, Cho Junsang, Hwang Wan Sik
Department of Materials Engineering, Korea Aerospace University, Goyang 10540, Korea.
Smart Drone Convergence, Korea Aerospace University, Goyang 10540, Korea.
Sensors (Basel). 2021 Jan 8;21(2):387. doi: 10.3390/s21020387.
A fast-response colorimetric ultraviolet-C (UVC) sensor was demonstrated using a gallium oxide (GaO) photocatalyst with small amounts of triethanolamine (TEOA) in methylene blue (MB) solutions and a conventional RGB photodetector. The color of the MB solution changed upon UVC exposure, which was observed using an in situ RGB photodetector. Thereby, the UVC exposure was numerically quantified as an MB reduction rate with the value of the photodetector, which was linearly correlated with the measured spectral absorbance using a UV-Vis spectrophotometer. Small amount of TEOA in the MB solution served as a hole scavenger, which resulted in fast MB color changes due to the enhanced charge separation. However, excessive TEOA over 5 wt.% started to block the catalytical active site on the surface of GaO, prohibiting the chemical reaction between the MB molecules and catalytic sites. The proposed colorimetric UVC sensor could monitor the detrimental UVC radiation with high responsivity at a low cost.
利用二氧化镓（GaO）光催化剂、亚甲基蓝（MB）溶液中的少量三乙醇胺（TEOA）以及传统的RGB光电探测器，展示了一种快速响应的比色紫外-C（UVC）传感器。UVC照射后MB溶液的颜色发生变化，这通过原位RGB光电探测器进行观察。由此，UVC照射量通过光电探测器的值以MB还原率进行数值量化，该值与使用紫外可见分光光度计测量的光谱吸光度呈线性相关。MB溶液中的少量TEOA充当空穴清除剂，由于电荷分离增强，导致MB颜色快速变化。然而，超过5 wt.%的过量TEOA开始阻塞GaO表面的催化活性位点，阻止了MB分子与催化位点之间的化学反应。所提出的比色UVC传感器能够以低成本高响应性监测有害的UVC辐射。
