Facile synthesis of nanostructured CuO for low temperature NO2 sensing

• Single step synthesis of nanosized crystallites CuO.
• Sensing low concentration of toxic NO2 gas at only 50 °C without any interference from oxygen.
• Temperature dependence sensing offered low activation energy of 0.18 eV.
• Adsorption kinetics is detailed based on the Elovich model.

Detection of environmental pollutant and health hazardous, nitrogen dioxide (NO2) is reported using nanostructured CuO particulates (NPs). Powder X-ray diffraction and field emission scanning electron microscopy were used to probe crystalline phase and morphological details, respectively. Small crystallites of ∼10–12 nm and a strain of 4% were found in the leafy structure of CuO. Raman studies further supported the presence of nanosized CuO phase. This is the first instance of utilizing CuO NPs to detect 5 ppm of NO2 even at a low operating temperature of 50 °C. The highest sensitivity for NO2 was observed at 150 °C, for the first time, in CuO NPs. A low activation energy of 0.18 eV was found for sensing process. The CuO NPs sensor responded to NO2 within a few seconds and recovered totally under a minute. The kinetics of the NO2 gas adsorption on the CuO film surface was described following the Elovich model.

Nanostructured p-type CuO exhibited a quick sensing reaction (TR) as well recovery (TREC) of NO2 toxic gas at low temperature of 50 °C.Figure optionsDownload as PowerPoint slide