Advanced Materials Division, Korea Research Institute of Chemical Technology, 141 Gajeongro, Yuseong-gu, Daejeon 34114, Republic of Korea.
Data Research Center, Korea Research Institute of Chemical Technology, 141 Gajeongro, Yuseong-gu, Daejeon 34114, Republic of Korea.
Int J Mol Sci. 2024 Jan 18;25(2):1172. doi: 10.3390/ijms25021172.
Graphene materials synthesized using direct laser writing (laser-induced graphene; LIG) make favorable sensor materials because of their large surface area, ease of fabrication, and cost-effectiveness. In particular, LIG decorated with metal nanoparticles (NPs) has been used in various sensors, including chemical sensors and electronic and electrochemical biosensors. However, the effect of metal decoration on LIG sensors remains controversial; hypotheses based on computational simulations do not always match the experimental results, and even the experimental results reported by different researchers have not been consistent. In the present study, we explored the effects of metal decorations on LIG gas sensors, with NO and NH gases as the representative oxidizing and reducing agents, respectively. To eliminate the unwanted side effects arising from metal salt residues, metal NPs were directly deposited via vacuum evaporation. Although the gas sensitivities of the sensors deteriorate upon metal decoration irrespective of the metal work function, in the case of NO gas, they improve upon metal decoration in the case of NH exposure. A careful investigation of the chemical structure and morphology of the metal NPs in the LIG sensors shows that the spontaneous oxidation of metal NPs with a low work function changes the behavior of the LIG gas sensors and that the sensors' behaviors under NO and NH gases follow different principles.
使用直接激光写入（激光诱导石墨烯；LIG）合成的石墨烯材料因其大的表面积、易于制造和成本效益而成为有吸引力的传感器材料。特别是，用金属纳米粒子（NPs）修饰的 LIG 已用于各种传感器，包括化学传感器以及电子和电化学生物传感器。然而，金属修饰对 LIG 传感器的影响仍然存在争议；基于计算模拟的假设并不总是与实验结果相匹配，甚至不同研究人员报告的实验结果也不一致。在本研究中，我们探讨了金属修饰对 LIG 气体传感器的影响，以 NO 和 NH 气体分别作为代表性的氧化剂和还原剂。为了消除金属盐残留物引起的不必要的副作用，通过真空蒸发直接沉积金属 NPs。尽管无论金属功函数如何，金属修饰都会使传感器的气体灵敏度恶化，但在 NH 暴露的情况下，NO 气体的金属修饰会提高传感器的灵敏度。对 LIG 传感器中金属 NPs 的化学结构和形态进行仔细研究表明，具有低功函数的金属 NPs 的自发氧化改变了 LIG 气体传感器的行为，并且传感器在 NO 和 NH 气体下的行为遵循不同的原理。
