Sun Yanhui, Fu Shouhang, Sun Shupeng, Cui Jiawen, Luo Zhixin, Lei Zefeng, Hou Yue
College of Information and Communication Engineering, Dalian Minzu University, Dalian 116600, China.
School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China.
ACS Appl Mater Interfaces. 2023 Nov 22;15(46):53714-53724. doi: 10.1021/acsami.3c12789. Epub 2023 Nov 7.
ZSM-5 zeolite is usually used in gas sensors as an auxiliary material to improve the gas-sensitive properties of other semiconductor materials, such as its molecular sieve properties and surface adsorption properties. Here, the gas-sensitive mechanism analysis of SnO/zeolite gas sensors is studied for the first time based on the perspective of zeolite as a band gap-tunable semiconductor that was reported recently. The gas-sensing mechanism of the zeolite/semiconductor has been modeled based on the surface charge theory, and the work function of the ZSM-5 zeolite has been revealed for the first time. A heterostructure of Ag and ZSM-5 was designed and compounded to tune the band gap of the ZSM-5 zeolite by the ammonia pool effect method. The band gap width of the zeolite decreases from 4.51 to 3.61 eV. A series of characterization techniques were used to analyze the distribution and morphology of silver nanoparticles in zeolites and the variation of the ZSM-5 band gap. Then, SnO/Ag@ZSM-5 sensors were fabricated, and the gas-sensing performances were measured. The gas-sensing results show that the SnO/Ag@ZSM-5 sensor has an improved response to formaldehyde in particular compared to the SnO sensor. The response value of the SnO/Ag@ZSM-5 sensor to 70 ppm formaldehyde reached 29.4, which is a 528% improvement compared to the SnO sensor. Additionally, the selectivity was greatly enhanced. This study provides a strategy for designing and developing higher-performance gas sensors.
ZSM-5沸石通常作为辅助材料用于气体传感器，以改善其他半导体材料的气敏性能，如其分子筛性能和表面吸附性能。在此，基于最近报道的沸石作为带隙可调半导体的视角，首次对SnO/沸石气体传感器的气敏机理进行了分析。基于表面电荷理论对沸石/半导体的气敏机理进行了建模，并首次揭示了ZSM-5沸石的功函数。设计并复合了Ag与ZSM-5的异质结构，通过氨池效应法调节ZSM-5沸石的带隙。沸石的带隙宽度从4.51 eV降至3.61 eV。采用一系列表征技术分析了银纳米颗粒在沸石中的分布和形貌以及ZSM-5带隙的变化。然后，制备了SnO/Ag@ZSM-5传感器，并测量了其气敏性能。气敏结果表明，与SnO传感器相比，SnO/Ag@ZSM-5传感器对甲醛的响应尤其得到了改善。SnO/Ag@ZSM-5传感器对70 ppm甲醛的响应值达到29.4，与SnO传感器相比提高了528%。此外，选择性也大大提高。该研究为设计和开发高性能气体传感器提供了一种策略。
