Abstract

PICASSO, Gino; BALBOA, Daniel  and  SUN-KOU, Rosario. Preparation of sensors based on Fe oxide doped with Pt for detection of methane. Rev. Soc. Quím. Perú [online]. 2015, vol.81, n.2, pp.171-184. ISSN 1810-634X.

Some sensors based on pure α-Fe₂O₃ (hematite) and doped with %Pt-loadings (respect to oxide) of 0,1; 0,2 y 0,3% have been prepared by precipitation method for detection of methane, sodium carbonate as precipitating agent and polyethylene glycol (PEG) as anti-agglomeration agent. The samples were characterized by X-ray diffraction (XRD), sorption of N₂ (BET method) and transmission electron microscopy (TEM). The XRD patterns showed that the crystalline structure of starting iron oxide has not been affected by the introduction of Pt as doping material. All the sensors depicted micro-mesoporous isotherms corresponding to type IV. TEM micrographs showed the average particle size of samples, ranging from 50 to 150 nm. Sensor tests were performed in a range of concentrations from 300 to 900 ppm and operation temperatures between 150 and 400 ºC. The sensor with 0,3% of Pt and 0,3% of PEG (20000) presented the highest gas response at 300ºC with an initial concentration of 900 ppm of methane probably due to the well-defined hematite crystalline structure, good dispersion of nanoparticles and the best contact surface over Pt surface.

Keywords : Gas sensor; methane detection; nanoparticles of Pd-doped α-Fe₂O₃.

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