Synergistic effects of SnO2 and Au nanoparticles decorated on WS2 nanosheets for flexible, room-temperature CO gas sensing

Submicrochains composed of massage ball-like WO3@CuWO4 have been prepared via a simple Cu2+ intercalation method. WO3@CuWO4 submicrochains sensors displayed excellent sensing performance to CO gas at room temperature.

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The Effect of Noble Metals on Co Gas Sensing Properties of In2O3 Nanoparticles

Applied Sciences ◽

10.3390/app11114903 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4903

Author(s):

JinAh Hwang ◽

Hyunsung Jung ◽

Hyo-Soon Shin ◽

Dae-Sung Kim ◽

Dong Soo Kim ◽

...

Keyword(s):

Noble Metals ◽

Au Nanoparticles ◽

Gas Sensing ◽

Pt Nanoparticles ◽

Depletion Region ◽

Gas Concentration ◽

Sensing Properties ◽

Gas Sensing Properties ◽

In2o3 Nanoparticles ◽

Co Gas

Three types of In2O3 nanoparticles decorated with Au, Pd and Pt nanoparticles, respectively, were synthesized by thermal decomposition method, and the effects of metal nanoparticles on their phase, microstructure, chemical state, carrier types were investigated with XRD, SEM/TEM, and XPS. Additionally, sensing properties to CO gas, such as sensitivity, etc., were examined with sensing apparatus. Au-decorated In2O3 nanoparticles exhibited the highest sensitivity to CO gas, with S = 5.59 at a 10 ppm CO gas concentration at 50 °C compared to Pd or Pt-decorated In2O3 nanoparticles. This can be interpreted as a much higher adsorption of oxygen molecules on the In2O3 surface due to the high oxygen vacancies in the In2O3 lattice, which generates an electron depletion region in the outer layer of In2O3 to sharply increase the resistance or the spill-over effect due to Au nanoparticles on In2O3. Au nanoparticles were observed in the TEM images and confirmed by XPS analysis.

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Improving the CO and CH4 Gas Sensor Response at Room Temperature of α-Fe2O3(0001) Epitaxial Thin Films Grown on SrTiO3(111) Incorporating Au(111) Islands

10.20944/preprints202106.0539.v1 ◽

2021 ◽

Author(s):

Aída Serrano ◽

Jesus López-Sánchez ◽

Iciar Arnay ◽

Rosalía Cid ◽

Maria Vila ◽

...

Keyword(s):

Gas Sensor ◽

Room Temperature ◽

Au Nanoparticles ◽

Gas Sensing ◽

Average Particle Size ◽

Average Particle ◽

Epitaxial Thin Films ◽

Island Type ◽

Before And After ◽

Crystallographic Axes

In this work epitaxial Au islands have been grown on epitaxial α-Fe2O3 thin film by pulsed laser deposition on SrTiO3(111) substrate. Both Au and α-Fe2O3 layer show an island-type growth with an average particle size of 40 and 62 nm, respectively. The crystallographic coupling of lattices is confirmed with a rotation of 30º between the in-plane crystallographic axes of α-Fe2O3(0001) structure and those of SrTiO3(111) substrate and between the in-plane crystallographic axes of Au(111) and those of α-Fe2O3(0001) structure. α-Fe2O3 is the only phase of iron oxide identified before and after its functionalization with Au nanoparticles. In addition, its structural character-istics are also preserved after Au deposition, with minor changes at short-range order. The func-tional character of the complex systems as gas sensor has been proven at room temperature. Con-ductance measurements of Au(111)/α-Fe2O3(0001)/ SrTiO3(111) system show that the incorpora-tion of Au islands on top of the α-Fe2O3(0001) layer induces an enhancement of the gas-sensing ac-tivity for CO and CH4 gas in comparison to a bare α-Fe2O3(0001) layer grown on SrTiO3(111).

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