Effect of effluent gas composition on characteristics of graphene oxide film based relative humidity sensor

• Published in: Measurement : journal of the International Measurement Confederation 2022-05, Vol.195, p.111156, Article 111156
• Main Authors: Seeneevassen, Seydiren, Leong, Ainan, Kashan, Mohammad Ali Mohammadzadeh, Swamy, Varghese, Ramakrishnan, N.
• Format: Article
• Language: English
• Subjects: Adsorption; Dehumidification; Effluent gas; Gas composition; Gases; Graphene; Graphene oxide; Humidification; Humidity; Hysteresis; Mass loading; Oxide coatings; Quartz; Quartz crystals; Relative humidity; Sensors
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2022.111156

[Display omitted] •Effluent gas composition impact on water vapor absorption state of GO film used in RH sensors.•Nitrogen as carrier gas leads to higher residual mass than that with air during initial humidification-dehumidification cycles.•Exposing GO film to multiple cycles of humidification saturates GO film, reduces hysteresis and improves sensitivity.•Ensuring appropriate level of GO film saturation, either of effluent gas can be used for RH sensing experiment. Nitrogen and synthetic air have been used as standard effluent gases in relative humidity (RH) sensing experiments, especially to characterise the dynamic sensing capabilities of RH sensors utilising graphene oxide (GO) as the sensing material. In the present work, we have used GO coated quartz crystal microbalance (QCM) as a tool to investigate the mass adsorption characteristics of samples subjected to multiple humidification-dehumidification cycles using N2 or synthetic air as the effluent gas. We identified that the residual mass adsorbed and retained by the GO film is on average 71.6% higher when using N2 in the initial humidification-dehumidification cycle and this subsequently impacted the hysteresis characteristics until the GO film saturated. To negate the impact of the effluent gas, the GO-based sample should be treated with multiple humidification and dehumidification cycles using either effluent gas.