Wang, Ziying, Sackmann, Andre, Gao, Shang, Weimar, Udo, Lu, Geyu, Liu, Sen, Zhang, Tong, and Barsan, Nicolae
Graphical abstract Highlights • In this work, the obtained Zn 2 SnO 4 -RGO hybrids exhibited outstanding sensing performance for detecting oxidizing gases (NO 2 and O 3) with very low cross sensitivities to reducing gases, such as C 2 H 5 OH, CH 3 COCH 3 and CO. • The Zn 2 SnO 4 -RGO based sensors exhibited high response values of up to 3.50 for 500 ppb NO 2 , which is higher than that for detection of 500 ppb O 3 (1.78) at 30 °C under 50% relative humidity (RH). • The surface reaction between Zn 2 SnO 4 -RGO hybrids and NO 2 can be concluded from Operando diffuse reflectance infrared Fourier transformed spectroscopy (Operando DRIFT). Abstract Highly selective oxidizing gas sensors are of great importance for environmental pollution monitoring. In this work, a hybrid material containing Zn 2 SnO 4 nanoparticles (NPs) and immobilized reduced graphene oxide (Zn 2 SnO 4 -RGO) was developed as a high performance gas sensing material for the detection of ppb-levels of oxidizing gases (NO 2 and O 3). The structural, morphological and compositional properties of the Zn 2 SnO 4 -RGO hybrids were systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), which demonstrated the successful anchoring of Zn 2 SnO 4 NPs on RGO nanosheets. The obtained Zn 2 SnO 4 -RGO hybrids exhibited outstanding sensing performance for detecting oxidizing gases (NO 2 and O 3) with very low cross sensitivities to reducing gases, such as C 2 H 5 OH, CH 3 COCH 3 and CO. The Zn 2 SnO 4 -RGO based sensors exhibited high response values of up to 3.50 for 500 ppb NO 2 , which is higher than that for detection of 500 ppb O 3 (1.78) at 30 °C under 50% relative humidity (RH). Moreover, the NO 2 sensing performances of Zn 2 SnO 4 -RGO-based sensors were investigated under various RH. In all cases, the sensors based on RGO and Zn 2 SnO 4 -RGO hybrids presented p-type behavior. The sensors based on Zn 2 SnO 4 -RGO hybrids also exhibited high response values of up to 3.62 for 1 ppm NO 2 at 50 °C in 80% RH, which is much higher than that of pure RGO (1.31). The excellent sensing performances are mainly ascribed to the synergetic effect of Zn 2 SnO 4 NPs and RGO. Furthermore, the surface reaction between Zn 2 SnO 4 -RGO hybrids and NO 2 can be concluded from Operando diffuse reflectance infrared Fourier transformed spectroscopy (Operando DRIFT). [ABSTRACT FROM AUTHOR]