Enhanced Humidity Sensing Properties of Surfactant-Free Hydrothermally Synthesized Tin Oxide Nanoparticles

Authors T. Preethi1, K. Senthil1, S. Ashokan1, R. Balakrishnaraja2, B. Sundaravel3, P. Saravanan4

1Advanced Materials Research Laboratory, Department of Physics, Bannari Amman Institute of Technology, Sathyamangalam 638401, Tamil Nadu, India

2Department of Food Technology, Bannari Amman Institute of Technology, Sathyamangalam 638401, Tamil Nadu, India

3Materials Science Group, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam 603102, Tamil Nadu, India

4Defense Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad 500058, India

Е-mail ksenthiludt@gmail.com
Issue Volume 13, Year 2021, Number 6
Dates Received 01 May 2021; revised manuscript received 03 December 2021; published online 20 December 2021
Citation T. Preethi, K. Senthil, et al., J. Nano- Electron. Phys. 13 No 6, 06003 (2021)
DOI https://doi.org/10.21272/jnep.13(6).06003
PACS Number(s) 73.61.Jc, 71.20.Mq, 88.40.hj, 88.40.jj
Keywords Metal oxides, SnO2 nanoparticles, Hydrothermal method, Optical properties (22) , Humidity sensor.

Metal oxide semiconductor nanomaterials have been widely used for applications in solar cells, batteries, gas sensors, optoelectronics, photocatalysis and hydrogen generation. Humidity sensors based on metal oxide semiconductors have shown significant contribution in the field of environmental monitoring, food technology and biotechnology. Among the various metal oxide semiconductors, tin oxide (SnO2) nanoparticles have generated more interest due to their excellent chemical stability, high transparency and low electrical sheet resistance. In the present work, SnO2 nanoparticles were synthesized by employing a simple hydrothermal process without using any surfactant. The synthesized nanoparticles were investigated using XRD, SEM, EDAX, UV-visible and humidity sensing measurements. The structural property of the sample investigated using XRD analysis indicated that the synthesized SnO2 nanoparticles have pure crystalline phase with a tetragonal crystal structure of the P42/mnm space group. The surface morphology analyzed using SEM micrograph showed agglomerated nanoparticles without any specific structure. Optical characterization using UV-visible spectroscopy indicated that the synthesized nanoparticles have strong absorption in the UV region. The humidity sensing property analyzed from the variation of electrical resistivity with relative humidity (% RH) showed good hysteresis behavior and the observed variation in electrical conduction is explained based on protonic conduction mechanism on the surface.

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