NO 2 gas sensing performance enhancement based on reduced graphene oxide decorated V 2 O 5 thin films

• Published in: Nanotechnology 2019-05, Vol.30 (22), p.224001
• Main Authors: Bhati, Vijendra Singh, Sheela, D, Roul, Basanta, Raliya, Ramesh, Biswas, Pratim, Kumar, Manish, Roy, M S, Nanda, K K, Krupanidhi, S B, Kumar, Mahesh
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/ab0321

Here, we demonstrate improved NO gas sensing properties based on reduced graphene oxide (rGO) decorated V O thin film. Excluding the DC sputtering grown V O thin film, rGO was spread over V O thin film by the drop cast method. The formation of several p-n heterojunctions was greatly affected by the current-voltage relation of the rGO-decorated V O thin film due to the p-type and n-type nature of rGO and V O , respectively. Initially with rGO decoration on V O thin film, current decreased in comparison to the pristine V O thin film, whereas depositing rGO film on a glass substrate drastically increased current. Among all sensors, only the rGO-decorated V O sensor revealed a maximum NO gas sensing response for 100 ppm at 150 °C, and it achieved an approximately 61% higher response than the V O sensor. The elaborate mechanism for an extremely high sensing response is attributed to the formation and modulation of p-n heterojunctions at the interface of rGO and V O . In addition, the presence of active sites like oxygenous functional groups on the rGO surface enhanced the sensing response. On that account, sensors based on rGO-decorated V O thin film are highly suitable for the purpose of NO gas sensing. They enable the timely detection of the gas, further protecting the ecosystem from its harmful effects.