Seo Min-Ho, Kang Kyungnam, Yoo Jae-Young, Park Jaeho, Lee Jae-Shin, Cho Incheol, Kim Beom-Jun, Jeong Yongrok, Lee Jung-Yong, Kim Byeongsu, Rho Junsuk, Yoon Jun-Bo, Park Inkyu
School of Biomedical Convergence Engineering, College of Information and Biomedical Engineering, Pusan National University, 49, Busandaehak-ro, Yangsan-si 43241, Gyeongsangnam-do, Republic of Korea.
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
ACS Nano. 2020 Dec 22;14(12):16813-16822. doi: 10.1021/acsnano.0c05476. Epub 2020 Dec 2.
This study proposes a reliable and self-powered hydrogen (H) gas sensor composed of a chemo-mechanically operating nanostructured film and photovoltaic cell. Specifically, the nanostructured film has a configuration in which an asymmetrically coated palladium (Pd) film is coated on a periodic polyurethane acrylate (PUA) nanograting. The asymmetric Pd nanostructures, optimized by a finite element method simulation, swell upon reacting with H and thereby bend the PUA nanograting, changing the amount of transmitted light and the current output of the photovoltaic cell. Since the degree of warping is determined by the concentration of H gas, a wide concentration range of H (0.1-4.0%) can be detected by measuring the self-generated electrical current of the photovoltaic cell without external power. The normalized output current changes are ∼1.5%, ∼2.8%, ∼3.5%, ∼5.0%, ∼21.5%, and 25.3% when the concentrations of H gas are 0.1%, 0.5%, 1.0%, 1.6%, 2%, and 4%, respectively. Moreover, because Pd is highly chemically reactive to H and also because there is no electrical current applied through Pd, the proposed sensor can avoid device failure due to the breakage of the Pd sensing material, resulting in high reliability, and can show high selectivity against various gases such as carbon monoxide, hydrogen sulfide, nitrogen dioxide, and water vapor. Finally, using only ambient visible light, the sensor was modularized to produce an alarm in the presence of H gas, verifying a potential always-on H gas monitoring application.
本研究提出了一种由化学机械操作的纳米结构薄膜和光伏电池组成的可靠且自供电的氢气（H₂）传感器。具体而言，该纳米结构薄膜具有这样一种结构，即在周期性聚氨酯丙烯酸酯（PUA）纳米光栅上不对称地涂覆钯（Pd）薄膜。通过有限元方法模拟优化的不对称Pd纳米结构在与H₂反应时会膨胀，从而使PUA纳米光栅弯曲，改变透射光量和光伏电池的电流输出。由于翘曲程度由H₂气体浓度决定，因此无需外部电源，通过测量光伏电池的自生电流就可以检测宽浓度范围的H₂（0.1 - 4.0%）。当H₂气体浓度分别为0.1%、0.5%、1.0%、1.6%、2%和4%时，归一化输出电流变化分别约为1.5%、2.8%、3.5%、5.0%、21.5%和25.3%。此外，由于Pd对H₂具有高化学反应活性，并且没有电流通过Pd，所提出的传感器可以避免由于Pd传感材料破裂导致的器件故障，从而具有高可靠性，并且对一氧化碳、硫化氢、二氧化氮和水蒸气等各种气体表现出高选择性。最后，仅使用环境可见光，该传感器被模块化以在存在H₂气体时发出警报，验证了潜在的持续H₂气体监测应用。
