Prep Aration And Gas-Sensing Property Of Ultra-fine NiO/SnO₂Nano-particles

Tin oxide (SnO2) is a typical n-type semiconductor (Eg=3.6eV at300K) and being studied as one of welcoming materials for detecting trace concentrations of toxic and flammable gases. The research developments of the SnO2gas sensor have been related in chapter1.The novel ultra-fine NiO/SnO2nano-particles (NPs) have been fabricated by creatively using carbon black (CB) as a frame and dispersing agent and applied as gas-sensing materials. In a typical synthesis, a precursor composed of mixed NiO/SnO2NPs and CB was initially prepared. Subsequently, the ultra-fine NiO/SnO2NPs were obtained by a thermal treatment towards the precursor. The final products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunauer Emmett Teller N2adsorption-desorption analysis. The ethanol-sensing tests showed that the ultra-fine NiO/SnO2NPs had both a low detection limit of the NiO/SnO2NPs sensor (5ppm), and fast response (2s) and recovery (3s) capabilities under5ppm concentration. As demonstrated, the ultra-fine NiO/SnO2NPs were highly promising for real-time monitoring gas sensor applications.