A Bandgap-optimization-induced Sensitivity Enhancement Effect in a Novel Ionization Gas Sensor with Composite Nanostructure

This letter reports a significant enhancement effect of sensitivity towards target volatile organic compounds (VOCs) induced by bandgap optimization on electrode surface, which is based on composite nanostructure. According to introducing titanium oxide (TiO2) nanowires into copper oxide (CuO) nanowires using atomic layer deposition (ALD), more extensive areas and more tips could strengthen subsequent discharge process. Furthermore, due to the low work function of decorated TiO2 and the bandgap optimization brought by above-mentioned hybrid structure, we believe that enhancement of field emission could be achieved. Compared with the ionization sensor of single nanostructure, the composite one provides stronger response, wider measuring range (10-1000ppm), lower energy consumption and better specificity. This heterostructure renders the ionization sensor suitable for working safely (0-50V) at room temperature and pressure.