Song Xinyu, Chen Bowen, Li Xinyi, Wang Jinpeng, Peng Ke, Lei Wen, Ming Xing
College of Physics and Electronic Information Engineering, Key Laboratory of Low-dimensional Structural Physics and Application, Education Department of Guangxi Zhuang Autonomous Region, Guilin University of Technology, Guilin 541004, PR China.
Guangxi Key Laboratory of Optical and Electronic Materials and Devices, MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guilin University of Technology, Guilin 541004, PR China.
Langmuir. 2025 Sep 2;41(34):23121-23131. doi: 10.1021/acs.langmuir.5c02929. Epub 2025 Aug 20.
Highly sensitive and reusable sensors for detecting harmful gas molecules are particularly important to reduce their harmful impacts on human health and the natural environment. Based on the density functional theory calculations, the adsorption properties and sensing performances of the monolayer penta-HgO material for nitrogen-containing toxic gas molecules (NO, NH, NO, and NO) were thoroughly explored. The adsorptions of NH, NO, and NO (NO) on the monolayer penta-HgO substrate are characterized by high (low) adsorption energy, significant (little) charge transfer, and short (long) adsorption distance, showing chemisorption (physisorption) properties. In addition, the band gap of penta-HgO decreases significantly after adsorbing NO and NO, resulting in a substantial increase in electrical conductivity. Meanwhile, due to the adsorption of NO, the substrate also generates an obvious magnetic moment. In this study, an efficient strategy to predict the direction and extent of charge transfer between the absorbed gas and substrate material is put forward by comparing the Fermi level and band edge positions of the adsorbent to the frontier molecular orbitals of the adsorbate. Furthermore, we propose a highly efficient resistive gas sensor based on the penta-HgO monolayer material for detecting NO and NO due to the obvious variations of the electronic structure and resultant prominent changes in the conductivity. Particularly, a Schottky diode sensor by fabricating a contacted interface between the penta-HgO monolayer and an Ag metal is designed according to the significantly changed work functions. The types and barrier heights of the metal-semiconductor contact (Ag-HgO) are modulated by the adsorption of NO or NO. Different current signals can be observed when a bias voltage of 0.4 eV is applied, enabling the selective identification of NO and NO. Additionally, the short recovery time after adsorbing NO and NO demonstrates the reusability of the sensor. The theoretical results of this study provide valuable insights for accelerating the discovery of potential sensing materials and promote innovative resistive sensors or Schottky diode sensors based on the pentagonal monolayer material for detecting nitrogen-containing gases.
用于检测有害气体分子的高灵敏度且可重复使用的传感器对于减少其对人类健康和自然环境的有害影响尤为重要。基于密度泛函理论计算，深入探究了单层五氧化汞材料对含氮有毒气体分子（NO、NH、NO和NO）的吸附特性和传感性能。NH、NO和NO（NO）在单层五氧化汞基底上的吸附具有高（低）吸附能、显著（微小）电荷转移以及短（长）吸附距离的特征，呈现出化学吸附（物理吸附）特性。此外，五氧化汞吸附NO和NO后带隙显著减小，导致电导率大幅增加。同时，由于NO的吸附，基底还产生明显的磁矩。在本研究中，通过比较吸附剂的费米能级和能带边缘位置与吸附质的前沿分子轨道，提出了一种预测吸附气体与基底材料之间电荷转移方向和程度的有效策略。此外，由于电子结构的明显变化以及电导率的显著改变，我们提出了一种基于五氧化汞单层材料的高效电阻式气体传感器用于检测NO和NO。特别地，根据功函数的显著变化，设计了一种通过在五氧化汞单层与Ag金属之间制造接触界面的肖特基二极管传感器。金属 - 半导体接触（Ag - HgO）的类型和势垒高度通过NO或NO的吸附进行调制。当施加0.4 eV的偏置电压时，可以观察到不同的电流信号，从而实现对NO和NO的选择性识别。此外，吸附NO和NO后的短恢复时间证明了该传感器的可重复使用性。本研究的理论结果为加速潜在传感材料的发现提供了有价值的见解，并促进了基于五角形单层材料用于检测含氮气体的创新电阻式传感器或肖特基二极管传感器的发展。
