Ngoc Hoa Tran Thi, Van Duy Nguyen, Hung Chu Manh, Van Hieu Nguyen, Hau Ho Huu, Hoa Nguyen Duc
International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) No 1 - Dai Co Viet Str. Hanoi Vietnam
Faculty of Electrical and Electronics Engineering, Phenikaa Institute for Advanced Study, Phenikaa University Yen Nghia, Ha-Dong District Hanoi 10000 Vietnam.
RSC Adv. 2020 May 6;10(30):17713-17723. doi: 10.1039/d0ra02266g. eCollection 2020 May 5.
SnO nanowires (NWs) are used in gas sensors, but their response to highly toxic gas HS is low. Thus, their performance toward the effective detection of low-level HS in air should be improved for environmental-pollution control and monitoring. Herein, AgO nanoparticle decorated SnO NWs were prepared by a simple on-chip growth and subsequent dip-coating method. The amount of decorated AgO nanoparticles on the surface of SnO NWs was modified by changing the concentration of AgNO solution and/or dipping times. Gas-sensing measurements were conducted at various working temperatures (200-400 °C) toward different HS concentrations ranging within 0.1-1 ppm. The selectivity of AgO-decorated SnO NW sensors for ammonia and hydrogen gases was tested. Results confirmed that the AgO-decorated SnO NW sensors had excellent response, selectivity, and reproducibility. The gas-sensing mechanism was interpreted under the light of energy-band bending by sulfurization, which converted the p-n junction into n-n, thereby significantly enhancing the sensing performance.
氧化锡纳米线（NWs）被用于气体传感器中，但其对剧毒气体硫化氢（HS）的响应较低。因此，为了实现环境污染控制与监测，需要提高它们对空气中低浓度硫化氢的有效检测性能。在此，通过一种简单的芯片上生长及后续浸涂法制备了AgO纳米颗粒修饰的SnO纳米线。通过改变硝酸银（AgNO）溶液的浓度和/或浸涂次数来调节SnO纳米线表面修饰的AgO纳米颗粒的数量。在200-400℃的不同工作温度下，针对0.1-1 ppm范围内的不同硫化氢浓度进行了气敏测量。测试了AgO修饰的SnO纳米线传感器对氨气和氢气的选择性。结果证实，AgO修饰的SnO纳米线传感器具有优异的响应、选择性和重现性。基于硫化作用导致的能带弯曲对气敏机理进行了解释，硫化作用将p-n结转变为n-n结，从而显著提高了传感性能。
