Electronic sensitization enhanced p-type ammonia gas sensing of zinc doped MoS2/RGO composites

S P Linto Sibi; M Rajkumar; Kamaraj Govindharaj; J Mobika; V Nithya Priya; R T Rajendra Kumar

doi:10.1016/j.aca.2023.340932

Electronic sensitization enhanced p-type ammonia gas sensing of zinc doped MoS₂/RGO composites

Anal Chim Acta. 2023 Apr 1:1248:340932. doi: 10.1016/j.aca.2023.340932. Epub 2023 Feb 2.

Authors

S P Linto Sibi¹, M Rajkumar², Kamaraj Govindharaj³, J Mobika⁴, V Nithya Priya¹, R T Rajendra Kumar³

Affiliations

¹ Department of Physics, PSG College of Arts and Science, Coimbatore, 641014, Tamil Nadu, India.
² Department of Physics, PSG College of Arts and Science, Coimbatore, 641014, Tamil Nadu, India. Electronic address: vmanirajkumar@gmail.com.
³ Advanced Materials and Devices Laboratory (AMDL), Department of Nanoscience and Technology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
⁴ Department of Physics, Nandha Engineering College, Erode, Tamil Nadu, 638052, India.

PMID: 36813461
DOI: 10.1016/j.aca.2023.340932

Abstract

Zinc (Zn) doping induced synergetic effects of defects engineering and heterojunction in Molybdenum disulphide/Reduced graphene oxide (MoS₂/RGO) effectively enhances the p-type Volatile organic compounds (VOC) gas sensing traits and helps in tailoring the over dependence on noble metals for surface sensitization. Through this work, we have successfully prepared Zn doped MoS₂ grafted on RGO employing an in-situ hydrothermal method. Optimal doping concentration of Zn dopants in the MoS₂ lattice triggered more active sites on the basal plane of MoS₂ with the aid of defects promoted by the zinc dopants. Effective intercalation of RGO further boost up the exposed surface area of Zn doped MoS₂ for further interaction of ammonia gas molecules. Besides, smaller crystallite size brought out by 5% Zn dopants aids in efficient charge transfer across the heterojunctions that further amplifies the ammonia sensing traits with a peak response of 32.40% along with a response time of 21.3 s and recovery time of 44.90 s. The as prepared ammonia gas sensor exhibited excellent selectivity and repeatability. The obtained results reveal that transition metal doping into the host lattice proves to be a promising approach for VOC sensing characteristics of p-type gas sensors and gives insight about the importance of dopants and defects for the development of highly efficient gas sensors in the future.

Keywords: Defect engineering; Heterojunction; RGO; VOC; Zinc doped MoS(2); p-type ammonia gas sensor.