Ling Yan, Yu Yunjiang, Tian Canxin, Zou Changwei
Key Laboratory of Advanced Coating and Surface Engineering, Lingnan Normal University, Zhanjiang 524048, China.
Research Center for Engineering Technology in Surface Strengthening of Guangdong Province, Lingnan Normal University, Zhanjiang 524048, China.
Nanomaterials (Basel). 2024 Nov 18;14(22):1844. doi: 10.3390/nano14221844.
The development of energy-efficient, sensitive, and reliable gas sensors for monitoring NO concentrations has garnered considerable attention in recent years. In this manuscript, TiO nanotube arrays/reduced graphene oxide nanocomposites with varying rGO contents (TiO NTs/rGO) were synthesized via a two-step method for room temperature NO gas detection. From SEM and TEM images, it is evident that the rGO sheets not only partially surround the TiO nanotubes but also establish interconnection bridges between adjacent nanotubes, which is anticipated to enhance electron-hole separation by facilitating electron transfer. The optimized TiO NTs/rGO sensor demonstrated a sensitive response of 19.1 to 1 ppm of NO, a 5.26-fold improvement over the undoped TiO sensor. Additionally, rGO doping significantly enhanced the sensor's response/recovery times, reducing them from 24 s/42 s to 18 s/33 s with just 1 wt.% rGO. These enhancements are attributed to the increased specific surface area, higher concentration of chemisorbed oxygen species, and the formation of p-n heterojunctions between TiO and rGO within the nanocomposites. This study provides valuable insights for the development of TiO/graphene-based gas sensors for detecting oxidizing gases at room temperature.
近年来，用于监测一氧化氮（NO）浓度的节能、灵敏且可靠的气体传感器的开发备受关注。在本论文中，通过两步法合成了具有不同氧化石墨烯（rGO）含量的二氧化钛（TiO）纳米管阵列/还原氧化石墨烯纳米复合材料（TiO NTs/rGO），用于室温下的NO气体检测。从扫描电子显微镜（SEM）和透射电子显微镜（TEM）图像可以明显看出，rGO片不仅部分包围TiO纳米管，还在相邻纳米管之间建立了互连桥，这有望通过促进电子转移来增强电子-空穴分离。优化后的TiO NTs/rGO传感器对1 ppm的NO表现出19.1的灵敏响应，比未掺杂的TiO传感器提高了5.26倍。此外，rGO掺杂显著提高了传感器的响应/恢复时间，仅1 wt.%的rGO就将其从24 s/42 s缩短至18 s/33 s。这些增强归因于比表面积的增加、化学吸附氧物种浓度的提高以及纳米复合材料中TiO和rGO之间p-n异质结的形成。本研究为开发用于室温下检测氧化性气体的TiO/石墨烯基气体传感器提供了有价值的见解。
