Production of a sensor for carbon monoxide or water vapor including a semi conductor metallic oxide, catalyst, and rheological agent
AssigneeKeele University
InventorEdward W. Williams
Life of this patent
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Abstract
A sensor to detect gases and vapors, particularly carbon monoxide and water vapor, at relatively low concentrations includes a substrate having a layer on a face of the substrate. The layer comprises a semi conductor metallic oxide (such as stannic oxide), a catalyst (such as platinum black), and a rheological agent (such as kieselguhr or sepiolite). The rheological agent induces porosity into the surface of the layer. The rheological agent affects the mixing and processing of the layer, and aids binding, resulting in a sensor with greater sensitivity and faster response.
Claims20
A sensor to detect emissions of gas or vapor, which comprises a substrate having a layer of a composition comprising a semiconductor metallic oxide, a catalyst and a rheological agent to induce porosity into the surface of the layer, the semiconductor metallic oxide being indium oxide or stannic oxide and the catalyst is present in the composition in an amount of from 3 to 30% by weight.
A method of constructing a sensor to detect emissions of gas or vapor, the method comprising the steps of:
- (a) forming a paste of a semi conductor indium oxide or stannic oxide, from 3-30% by weight of the catalyst, and a rheological agent, in water;
- (b) applying the paste to a substrate to form a layer;
- and
- (c) annealing the layer at elevated temperature to form a hardened layer having a porous surface.
Dependencies are inferred from the claim text.