The efficacy of polyvinylpyrrolidone (PVP)/CuO nanocomposite as an appropriate room temperature humidity sensing material: fabrication of highly sensitive capacitive resistive type humidity sensor

• Published in: Journal of materials science. Materials in electronics 2020-05, Vol.31 (10), p.7698-7707
• Main Authors: Khan, Hizb Ullah, Tariq, Muhammad, Shah, Mutabar, Jan, Muhammad Tariq, Iqbal, Mahmood, Khan, Jehangeer, Ahsan, Abdul Razaq, Rahim, Abdur
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemical reduction; Chemistry and Materials Science; Comparative studies; Copper oxides; Detection; Humidity; Materials Science; Nanocomposites; Optical and Electronic Materials; Polyvinylpyrrolidone; Room temperature; Sensors; Substrates
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-03305-x

Polyvinylpyrrolidone (PVP)/CuO composites were synthesized using polymerization method for humidity sensing. The CuO nanosheets for composite were prepared by chemical reduction method. It was found that the PVP/CuO nanocomposite has compact structure while PVP was porous in nature. Humidity sensors using PVP, CuO, and PVP/CuO nanocomposite were fabricated by simple-drop casting method. Interdigitated copper electrodes with 50 μm gap were used for the casting of substrate in dust-free environment. The comparative study was performed at a constant temperature of 300 K with different frequencies using LCR meter. Resistance of the sensors was decreased to zero as the humidity concentration increased from 25 to 95% RH in the sensing assembly. An appreciable increase of 58.5–4370 nF (sensitivity 71,660%/%RH) was observed in capacitance with the increase of humidity level from 25 to 95% RH at 0.1 kHz frequency. A small hysteresis value of 6.7%, 1.8%, and 2.1% were observed for PVP, CuO, and PVP/CuO nanocomposite. When compared with PVP and CuO, an efficient response was recorded for PVP/CuO nanocomposite toward humidity sensing.