Patching sulfur vacancies: A versatile approach for achieving ultrasensitive gas sensors based on transition metal dichalcogenides

Xiangcheng Liu; Yue Niu; Duo Jin; Junwei Zeng; Wanjiang Li; Lirong Wang; Zhipeng Hou; Yancong Feng; Hao Li; Haihong Yang; Yi-Kuen Lee; Paddy J French; Yao Wang; Guofu Zhou

doi:10.1016/j.jcis.2023.06.092

Patching sulfur vacancies: A versatile approach for achieving ultrasensitive gas sensors based on transition metal dichalcogenides

J Colloid Interface Sci. 2023 Nov:649:909-917. doi: 10.1016/j.jcis.2023.06.092. Epub 2023 Jun 17.

Authors

Xiangcheng Liu¹, Yue Niu², Duo Jin¹, Junwei Zeng¹, Wanjiang Li¹, Lirong Wang³, Zhipeng Hou³, Yancong Feng¹, Hao Li¹, Haihong Yang⁴, Yi-Kuen Lee⁵, Paddy J French⁶, Yao Wang⁷, Guofu Zhou¹

Affiliations

¹ Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, PR China.
² Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, PR China; School of Physical Sciences, Great Bay University, Dongguan 523000, PR China. Electronic address: niuyue@gbu.edu.cn.
³ Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics South China Normal University, Guangzhou 510006, PR China.
⁴ Department of Thoracic Oncology, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510006, PR China.
⁵ Department of Mechanical & Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region.
⁶ BE Laboratory, EWI, Delft University of Technology, Delft 2628CD, the Netherlands.
⁷ Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, PR China. Electronic address: wangyao@m.scnu.edu.cn.

PMID: 37390538
DOI: 10.1016/j.jcis.2023.06.092

Abstract

Transition metal dichalcogenides (TMDCs) garner significant attention for their potential to create high-performance gas sensors. Despite their favorable properties such as tunable bandgap, high carrier mobility, and large surface-to-volume ratio, the performance of TMDCs devices is compromised by sulfur vacancies, which reduce carrier mobility. To mitigate this issue, we propose a simple and universal approach for patching sulfur vacancies, wherein thiol groups are inserted to repair sulfur vacancies. The sulfur vacancy patching (SVP) approach is applied to fabricate a MoS₂-based gas sensor using mechanical exfoliation and all-dry transfer methods, and the resulting 4-nitrothiophenol (4NTP) repaired molybdenum disulfide (4NTP-MoS₂) is prepared via a sample solution process. Our results show that 4NTP-MoS₂ exhibits higher response (increased by 200 %) to ppb-level NO₂ with shorter response/recovery times (61/82 s) and better selectivity at 25 °C compared to pristine MoS₂. Notably, the limit of detection (LOD) toward NO₂ of 4NTP-MoS₂ is 10 ppb. Kelvin probe force microscopy (KPFM) and density functional theory (DFT) reveal that the improved gas sensing performance is mainly attributed to the 4NTP-induced n-doping effect on MoS₂ and the corresponding increment of surface absorption energy to NO₂. Additionally, our 4NTP-induced SVP approach is universal for enhancing gas sensing properties of other TMDCs, such as MoSe₂, WS₂, and WSe₂.

Keywords: 2D materials; Gas sensing; N-doping; Patching sulfur vacancies; Transition metal dichalcogenides.