Room temperature NO2 sensing: what advantage does the rGO-NiO nanocomposite have over pristine NiO?

• Published in: Physical chemistry chemical physics : PCCP Vol. 17; no. 22; pp. 14903 - 14911
• Main Authors: Zhang, Jian, Zeng, Dawen, Zhao, Shiqian, Wu, Jinjin, Xu, Keng, Zhu, Qiang, Zhang, Guozhu, Xie, Changsheng
• Format: Journal Article
• Language: English
• Published: England 14.06.2015
• ISSN: 1463-9084
• DOI: 10.1039/c5cp01987g

In recent years, there has been increasing interest in synthesis of reduced graphene oxide (rGO)-metal oxide semiconductor (MOS) nanocomposites for room temperature gas sensing applications. Generally, the sensitivity of a MOS can be obviously enhanced by the incorporation of rGO. However, a lack of knowledge regarding how rGO can enhance gas-sensing performances of MOSs impedes its sensing applications. Herein, in order to get an insight into the sensing mechanism of rGO-MOS nanocomposites and further improve the sensing performances of NiO-based sensors at room temperature, an rGO-NiO nanocomposite was synthesized. Through a comparison study on room temperature NO2 sensing of rGO-NiO and pristine NiO, an inverse gas-sensing behavior in different NO2 concentration ranges was observed and the sensitivity of rGO-NiO was enhanced obviously in the high concentration range (7-60 ppm). Significantly, the stimulating effect of rGO on the recovery rate was confirmed by the sensing characteristics of rGO-NiO that was advantageous for the development of NO2 sensors at room temperature. By comprehending the electronic interactions between the rGO-MOS nanocomposite and the target gas, this work may open up new possibilities for further improvement of graphene-based hybrid materials with even higher sensing performances.