Synthesis of the PS/CdSeNRs composite for room temperature NO2 gas sensing

In the present work, the cadmium selenide nanorods (CdSeNRs) have been successfully synthesized onto porous silicon (PS) layer via hydrothermal method. The structural and surface morphology of PS/CdSeNRs composite were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The CdSeNRs were homogeneously distributed at the PS surface with the presence of some microvoids, which contributes to the adsorption/desorption process of NO(2)gas molecules. At the optimum working temperature (25 degrees C), the PS/CdSeNRs composite showed greater gas response than that of the PS layer at 1 ppm NO2. Simultaneously, the PS/CdSe composite sensor displayed high gas response, excellent repeatability and perfect stability toward NO(2)gas owing to its large specific surface area, particular structure, and great amounts of oxygen vacancies. The weak responses of the composite sensor to great concentrations of other reducing gases indicate an excellent selectivity to NO(2)gas.