Speaker
Description
The development of highly sensitive gas sensors that do not require elevated operating temperatures remains critical for the safe detection of liquefied petroleum gas (LPG). Nickel cobaltite (NiCo2O4) is a p-type bimetallic oxide that has been extensively studied for the detection of volatile organic compounds, although its potential for LPG detection has received limited attention. NiCo2O4-based heterostructures were synthesized via a two-step hydrothermal process, incorporating secondary Co3O4 or NiO phases to form heterostructured architectures with increased active sites and modified electronic properties. The influence of additional Co or Ni cations on the structural, morphological, and LPG gas sensing properties of NiCo2O4 was systematically investigated.
Powder X-ray diffraction analysis confirmed the coexistence of spinel NiCo2O4 with Co3O4 or NiO phases. The microstructural analysis revealed that the crystallite size reduced from 16 nm for pristine NiCo2O4 to 11 nm or 10 nm due to secondary Co3O4 or NiO phases, respectively, indicative of increased defect density. X-ray photoelectron spectroscopy analysis confirmed the presence of additional Co2+/Co3+ or Ni2+ cations, which played a key role in modifying charge carrier concentration and promoting the adsorption of oxygen species on the sensor surface. As a result, exposure to LPG at 25-150℃ caused stronger modulation of the depletion layer, leading to a markedly improved sensing response compared to pristine NiCo2O4. This work demonstrates the potential of compositional engineering in bimetallic oxides for low-temperature detection of combustible gases.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |