PdPt Bimetal-Functionalized SnO₂ Nanosheets: Controllable Synthesis and its Dual Selectivity for Detection of Carbon Monoxide and Methane

Abstract

Bimetallic nanoparticles (NPs) usually exhibit some novel properties due to the synergistic effects of the two distinct metals, which is expected to play an important role in the field of gas sensing. PdPt bimetal NPs with Pd-rich shell and Pt-rich core were successfully synthesized and used to modify SnO 2 nanosheets. The 1P-PdPt/SnO 2 -A sensor obtained by self-assemblies of PdPt NPs exhibited temperature-dependent dual selectivity to CO at 100 °C and CH 4 at 320 °C. Furthermore, the sensor possessed good long term stability and antihumidity interference. The activation energy of adsorption for CO and CH 4 were estimated by the temperature-dependent response process modeled using Langmuir adsorption kinetics, which proved that the lower activation energy of adsorption corresponded to better sensing performance. The gas-sensing mechanism based on the diffusion depth of the tested gas in the sensing layer was discussed. The dramatically improved sensing performance could be ascribed to the high catalytic activity of PdPt bimetal, the electron sensitization of PdO, and Schottky barrier-type junctions at the interface between SnO 2 and PdPt NPs. Our present results demonstrate that bimetal NPs with special structure and components can significantly improve the gas-sensing performance of metal oxide semiconductor and the obtained sensor has great potential in monitoring coal mine gas.

Bimetallic Nanocrystals: Structure, Controllable Synthesis and Applications in Catalysis, Energy and Sensing

“…Many electrochemical sensors are called electronic tongues, and research focuses on the development of liquid sensors and chemometric analysis of data. [198]. Copyright American Chemical Society, 2019.…”

“…As shown in Figure 16 a–d, PdPt NPs displayed good dispersion with a narrow size distribution from 2 to 3.5 nm (mean size = 2.7 nm). The sensing performance demonstrated that a PdPt bimetal-functionalized SnO 2 nanosheets sensor could detect carbon monoxide at 100 °C and methane at 320 °C ( Figure 16 g,h) [ 198 ].…”

“… ( a , b ) TEM images and ( c ) HRTEM image of PdPt bimetal (inset ( b ) is the particle size distribution), ( d ) HAADF-STEM image, corresponding EDS mapping for ( e ) Pd, ( f ) Pt, selectivity of the obtained sensors on exposure to 1000 ppm methane and 50 ppm other gases at different working temperatures ( g ) 100 °C and ( h ) 320 °C. Reproduced with permission from [ 198 ]. Copyright American Chemical Society, 2019.…”

Design of Carbon Monoxide (CO) and Smoke Sensor, and Creation of Warning System with Fixed Telephone Call Using These Sensors

“…Such studies attract intensive attention in our country and in the world (Bui et al, 2019;Li et al, 2019;Okamoto et al, 1980). Especially, CO gas sensor design is not available in our country.…”

Formaldehyde gas sensor with extremely high response employing cobalt-doped SnO2 ultrafine nanoparticles

“…Figure 2 (a), which visually shows the existence of the Sn and O peaks.Figure 2 (b)shows the XPS spectrum of Sn. The purple curve represents pure SnO 2 NPs with two distinct peaks at 495.0 eV and 486.7 eV, corresponding to Sn 4+ 3d 3/2 and Sn 4+ 3d 5/2 , respectively26,27 . Besides, as the proportion of Co doping increases, it can be clearly found that the Sn 3d peak shifts significantly.…”