Selective sensing characteristics of Fe doped and (Fe, N, O) co-doped molybdenum disulfide toward CO, CO2, and NH3 gases: a first-principles investigation

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요약

RSC Adv., 2026, 16,19334-19351DOI: 10.1039/D5RA09296E, Paper Open Access &nbsp This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.Thi H. Ho, Khiet An Vuong, Le Phuong Truong, Nguyen Hai Dang, Minh-Thuan Pham, D. M…

본문

Selective sensing characteristics of Fe doped and (Fe, N, O) co-doped molybdenum disulfide toward CO, CO2, and NH3 gases: a first-principles investigation

* Corresponding authors

a Laboratory for Computational Physics, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, Vietnam
E-mail: [email protected], [email protected]

b Faculty of Mechanical, Electrical, and Computer Engineering, Van Lang School of Technology, Van Lang University, Ho Chi Minh City, Vietnam

c College of Natural Sciences, Can Tho University, Can Tho City, Vietnam

d Faculty of Mechatronics and Electronics, Lac Hong University, Dong Nai Province, Vietnam

e Faculty of Basic Sciences, Nam Can Tho University, Can Tho City, Vietnam

f Center for Environmental Toxin and Emerging-Contaminant Research, Cheng Shiu University, Kaohsiung City, Taiwan

g Institute of Theoretical and Applied Research, Duy Tan University, Ha Noi 100000, Vietnam

h School of Engineering and Technology, Duy Tan University, Da Nang 550000, Vietnam

i School of Education, Can Tho University, Can Tho City, Vietnam

Abstract

This work investigates the effect of supercell size and effective dopant concentration on Fe-doped and Fe–N/Fe–O co-doped MoS2 systems toward CO, CO2, NH3 adsorption using first-principles calculations. The results show that supercell size is a key physical factor governing the predicted properties of these systems. As the supercell expands from a 2 × 2 × 1 supercell to a 4 × 4 × 1 supercell, the effective dopant concentration decreases markedly, leading to substantial changes in the electronic structure, while the magnetic character remains largely preserved. In particular, Fe–MoS2, Fe–N–MoS2, and Fe–O–MoS2 systems evolve from metallic or half-metallic behavior in smaller supercells toward semiconducting states in the 4 × 4 × 1 model. Adsorption energies also vary with supercell size, although less systematically than the electronic properties. Among the studied systems, Fe–N–MoS2 shows the most noticeable response toward NH3 in the high-concentration 2 × 2 × 1 regime, with an adsorption energy of −0.264 eV, an adsorption distance of 1.5267 Å, evident Fe-3d/N-2p hybridization, and stronger charge transfer. In addition, the calculated sensing descriptors indicate a measurable NH3 response, including a maximum selectivity of 2.24%, an electronic sensitivity of 98.9% at the Fermi level, and a recovery time on the order of 10−8 s at 300 K. Overall, these results demonstrate that the predicted sensing behavior of doped MoS2 is strongly dependent on supercell size, with the effective dopant concentration governing both the electronic structure and adsorption characteristics of these two-dimensional systems.