Hydrothermal Synthesis of Nanostructured NiO: effect of Synthesis Conditions on Morphology of Materials

NOx gases are deadly poisons and high-value environmental pollutants: NO2 is one of the most highly toxic gases, cause damage to the lungs, cardiovascular system, and upper respiratory tract when humans inhale it even in low concentrations (ppm level). Acid rains, eutrophication and depletion of the protective stratosphere ozone layer are linked to NOx species. The permissible exposure levels: 5 ppm NOx by OSHA, 0.1 g/mile for light cars and trucks by EPA. Why Tungsten oxide nanowires for sensing NO2? Tungsten oxide (WO3), a wide bandgap (~2.8 eV) n-type semiconductor, has attracted extensive attention because of its distinctive physical and chemical properties which exhibits strong NOx sensing character especially if it possesses large surface area. Hydrothermal and/or solvothermal, are simple, low cost, and scalable synthesis methods for synthesizing nanostructured metal oxides. Attempts to control the synthesis of WO3 nanostructures with small crystalline size and superior surface properties is still a primary challenge for scientists worldwide.