Ethanol Sensors Based on Porous In2O3 Nanosheet-Assembled Micro-Flowers

Abstract

By controlling the hydrothermal time, porous In2O3 nanosheet-assembled micro-flowers were successfully synthesized by a one-step method. The crystal structure, microstructure, and internal structure of the prepared samples were represented by an x-ray structure diffractometry, scanning electron microscopy, and transmission electron microscopy, respectively. The characterization results showed that when the hydrothermal time was 8 h, the In2O3 nano materials presented a flower-like structure assembled by In2O3 porous nanosheets. After successfully preparing the In2O3 gas sensor, the gas sensing was fully studied. The results show that the In2O3 gas sensor had an excellent gas sensing response to ethanol, and the material prepared under 8 h hydrothermal conditions had the best gas sensing property. At the optimum working temperature of 270 °C, the highest response value could reach 66, with a response time of 12.4 s and recovery time of 10.4 s, respectively. In addition, the prepared In2O3 gas sensor had a wide detection range for ethanol concentration, and still had obvious response for 500 ppb ethanol. Furthermore, the gas sensing mechanism of In2O3 micro-flowers was also studied in detail.

Pd/Pt-Bimetallic-Nanoparticle-Doped In2O3 Hollow Microspheres for Rapid and Sensitive H2S Sensing at Low Temperature

“…The sensor responds very quickly after contacting H 2 S, and the response time is only 3 s (T Response = 3 s). According to the characterization, the structure of 1 at% Pd/Pt-In 2 O 3 is porous and has a specific surface area of 58.3704 m 2 /g, which enables the gas to diffuse into the interior of the material; there are many active sites on the surface of the material where hydrogen sulfide can be bound, which accelerates the response speed [ 20 ]. In addition, a large amount of chemically adsorbed oxygen is distributed on the material surface due to the overflow effect of the Pt NPs, which further shortens the response time [ 25 ].…”

“…Liu et al [ 19 ] synthesized an In 2 O 3 porous pompon assembled from 2D nanosheets using the hydrothermal method, and its response to 50 ppm ethanol was 3.4. Qin et al [ 20 ] synthesized porous In 2 O 3 nanosheet-assembled microflowers, which had a response of 66 to 100 ppm ethanol and could respond (12.4 s) and recover (10.4 s) quickly. This was because the porous structures provided more gas adsorption sites and allowed gas molecules to diffuse to the depth of the material.…”

Current Trends in Nanomaterials for Metal Oxide-Based Conductometric Gas Sensors: Advantages and Limitations—Part 2: Porous 2D Nanomaterials

“…Some of the problems associated with the excessive thickness of nanosheets have been solved on the basis of new technologies [ 22 , 40 ] using hydro/solvothermal synthesis [ 41 , 42 ], the interface-mediated synthesis method [ 43 ], 2D-oriented attachment method [ 44 ], 2D-templated synthesis [ 45 ], self-assembly of nanocrystals [ 46 ], and the on-surface synthesis method [ 47 ].…”

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“…In recent years, metal oxide semiconductors have been widely used as gas sensors for the detection of toxic and flammable gases. – The GO/CuO nanohybrid has properties such that the sensor made out of it shows high efficiency compared to the sensors made up of individual components. The electrical properties can change drastically due to the binding of two different materials, and one can get improved efficiency and sensitivity.…”