Low-cost reduced graphene oxide-based conductometric nitrogen dioxide-sensitive sensor on paper

Area of Science:

• Materials Science
• Chemical Sensors
• Nanotechnology

Background:

• Graphene oxide (GO) is a promising material for sensor applications.
• Developing low-cost, scalable sensing technologies is crucial for environmental monitoring.
• Nitrogen dioxide (NO2) is a key air pollutant requiring sensitive detection methods.

Purpose of the Study:

• To present a fabrication concept for a low-cost sensor device using reduced graphene oxide (rGO) on a porous paper substrate.
• To investigate the sensing performance of rGO-based sensors for NO2 detection.
• To explore methods for enhancing sensor recovery.

Main Methods:

• Fabrication of sensors using reduced graphene oxide (rGO) on a porous paper substrate.
• Characterization using conductivity, capacitance measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS).
• Evaluation of sensor response to NO2, including the effects of reducing agents, GO flake size, and film thickness.

Main Results:

• The rGO-based sensor demonstrated sensitivity to NO2.
• Optimal sensitivity was achieved with a thin (10-nm) hydrazine-reduced GO layer, showing a 70% resistance reduction upon exposure to 10 ppm NO2.
• The sensor exhibited sensitivity suitable for detecting sub-parts per million levels of NO2.
• UV irradiation accelerated the desorption of gas molecules, enhancing sensor recovery.

Conclusions:

• A simple and scalable fabrication method for low-cost NO2 sensors using rGO on paper was successfully developed.
• The developed sensor offers high sensitivity and rapid recovery, making it suitable for environmental NO2 monitoring.
• The fabrication concept is adaptable for other sensing materials, indicating broad applicability.