Researchers have developed sensors that are capable of detecting low concentrations of liquefied petroleum gas1. These sensors could potentially be used for detecting liquefied petroleum gas in both indoor and outdoor environments.

Although sensors based on porous thin films can trap gas molecules, the low surface area of thin films produced from nanowires reduces their ability to capture gas molecules. One way to overcome this problem is to use thin films containing aligned nanorods, since they have larger surface areas than nanowire-based films.

The researchers fabricated sensors based on two types of zinc ferrite thin films: one with mixed-shaped nanorods and the other with vertically aligned nanorods. They then tested the efficacy of these thin-film-based sensors in detecting liquefied petroleum gas at room temperature.

The researchers found that the sensor with vertically aligned nanorods trapped and detected molecules of liquefied petroleum gas more efficiently than the sensor with mixed-shaped nanorods. They attributed this enhanced response of the sensor with vertically aligned nanorods to its open porous network of nanorods, which gives the sensor a greater surface area for capturing and reacting with gas molecules. The gas molecules attached to the surfaces of the sensors by forming chemical bonds and through weak forces such electrostatic attraction.

The sensor with vertically aligned nanorods retained its ability to detect gas molecules even three months after fabrication, indicating its stability and reliability.

“The study results demonstrate that the sensor with vertically aligned nanorods are promising for developing cheap and high-performance sensors for liquefied petroleum gas,” says Satyendra Singh, lead author of the study.