Study of CuO–SnO₂heterojunction nanostructures for enhanced CO gas sensing properties

Abstract

In this study, a facile hydrothermal method was adopted to fabricate SnO 2 and CuO-SnO 2 nanoparticles. The CuO content was chosen as 5 mol.-% (sample 1), 10 mol.-% (sample 2) and 15 mol.-% (sample 3). Microstructures and surface morphologies for all samples were characterised by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). A systematic comparison study reveals an enhanced gas sensing performance for the CuO-SnO 2 gas sensor towards CO gas. The improved gas sensing properties are attributed to the formation of p-n junctions and the absorbed oxygen species as well as to the heterojunctions of the CuO to the SnO 2 nanoparticles which provide additional reaction rooms. The results represent an advance of heterojuction nanostructures in further enhancing the functionality of gas sensors, and this simple method could be applicable to many sensing materials.

Metal oxide nanostructures for sensor applications

“…The sensor exhibited response to ppb-level ethanol and response time was 1 s. In another study, gas sensors fabricated from SnO2-SnO nanocomposite with p-n heterojunctions exhibited an enhanced sensing performance for NO2 gas detection, with limit of detection and sensitivity of 0.1 ppm and 0.26 ppm −1 , respectively [518]. Another p-n heterojunction was demonstrated with CuO-SnO2 gas sensors for CO gas [519]. A sensor based on a hierarchical CoO/SnO2 heterojunction demonstrated response up to 145 when exposed to 100 ppm ethanol gas.…”

Low-Voltage-Driven SnO2-Based H2S Microsensor with Optimized Micro-Heater for Portable Gas Sensor Applications

“…When the SnO 2 surface is exposed to a reductive gas (H 2 S), the reductive gas (H 2 S) upon reacting with the oxygen species (O 2 − , O − , and O 2− ) reduces the concentration of the oxygen species on this surface, thereby increasing the electron concentration [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Oxygen species with different forms (O 2 − , O − and O 2− ), which are adsorbed on the SnO 2 surface, are reliant on sensing temperature; therefore, controlling the temperature of H 2 S sensor is vital.…”

Visible light active heterostructured photocatalyst system based on CuO plate‐like particles and SnO2 nanofibers

“…The study has shown that the composite powders could exhibit higher photocatalytic activity compared to standard Degussa P25 TiO 2 nanoparticles. Due to this success, CuO–SnO 2 heterostructures were then produced by others using different methods such as electrospinning, spray pyrolysis, combustion synthesis, solution casting, doctor blade, and hydrothermal synthesis in thin film, fiber and powder forms to reveal their potential in gas sensing, H 2 production, dye degradation, and Li‐ion battery applications . Recently, Wang et al, prepared SnO 2 ‐CuO hollow fibers in the presence of camphene as the morphology controlling agent.…”