C activity, non-toxic, very good chemical stability, and low price tag [214]. With theChemosensors 2021, 9, 284. https://doi.org/10.3390/chemosensorshttps://www.mdpi.com/journal/chemosensorsChemosensors 2021, 9,2 ofincreasing degree of scientific analysis, the properties of pure ZnO and TiO2 can no longer meet the necessary needs. Following continuous exploration, the related properties might be enhanced via the doping mechanism [25]. Park et al. prepared TiO2 -ZnO core hell nanofibers as sensing components for the dynamic detection of oxygen [26]. It is actually located that it has excellent sensitivity and reproducibility. Graphene is really a two-dimensional honeycomb carbon material composed of singlelayer carbon atoms. It has great conductivity [27], rich sources [28], and high thermal conductivity [29]. Graphene has large specific surface region [30] and very good adsorption activity [31] because of its single-layer folded structure [32]. As a result of its special properties, it has a wide range of applications in the field of electronic sensing. Metal oxides normally face issues for instance higher operating temperature and poor selectivity to organic gases. To avoid defects, we intended to introduce the two-dimensional material graphene, forming the ternary nanomaterial ZnO-TiO2 -rGO. Johra et al. in 2015 have ready RGO-TiO2 -ZnO nanocomposites by the hydrothermal reduction N1-Methylpseudouridine Purity approach as a photocatalytic application [33]. In this paper, a straightforward hydrothermal system was employed to prepare the ternary nanomaterial ZnO-TiO2 -rGO for gas sensor applications. The ZnO-TiO2 -rGO sensor has excellent stability, reproducibility, and selectivity for butanone vapor at low temperatures. The sensor is also capable of detecting lower butanone vapors and has very good selectivity to butanone vapors. The ternary composite nanomaterial ZnO-TiO2 -rGO drastically improved its gas-sensitive efficiency. two. Supplies and Characterization Instruments 2.1. Reagents and Instruments C12 H28 O4 Ti (AR) and CH3 COOH (AR) had been each purchased from Shanghai Macklin Biochemical Co., Ltd. NaOH (AR) and (CH3 COO)2 Zn (AR) were each purchased from Sinopharm Group Chemical Reagent Co., Ltd. C2 H5 OH (AR) was bought from Tianjin Fuyu Fine Chemical Co., Ltd. AR is analytical pure reagent. The microscopic morphology and crystal structure on the nanomaterials have been characterized and imaged applying the instruments which include high-resolution transmission electron microscopy (HRTEM, JEOLJEM-2010, Beijing, China), X-ray photoelectron spectrometry (XPS, Thermo ScientificTM K-AlphaTM+ spectrometer, Beijing, China), field-emission Biotin-azide web scanning electron microscopy (SEM, Hitachi, Tokyo, Japan), and X-ray diffraction (XRD, SmartLab SE, Tokyo, Japan). 2.2. Supplies Preparation Initially, 1.five mL of C12 H28 O4 Ti, 50 mL of C2 H5 OH, and 1 mL of CH3 COOH were mixed within the same beaker and sonicated for 20 min. The mixed resolution was loaded into the reactor and reacted at 200 for 1 h. The item obtained was dried at 60 C by centrifuging twice with water and ethanol, respectively. This approach yielded the nanomaterial TiO2 . Then, 270 mg (CH3 COO)2 Zn was stirred nicely with 50 mL of deionized water, and 1 M NaOH solution was added dropwise to pH = 12. The mixed resolution was poured into a appropriate capacity reactor and reacted at 200 C for 1 h. Precisely the same was centrifuged and dried at 60 C. This method yields the solution ZnO. Then, 1.5 mL of C12 H28 O4 Ti, 50 mL of C2 H5 OH, and 1 mL of CH3 COOH were mixed within the similar beaker and sonicated for 20 min.