A Multiband-Spectra-Photocatalytic Synergy Material

To solve the photocatalyst's problems of low quantum yield and low solar energy conversion efficiencies, and to achieve generating negative air ion and antibacterial functions , a new material named multiband-spectra-photocatalytic synergy material(MSPSM) is developed. The MSPSM is prepared by the process of compounding nano-TiO2 doped with rare-earth sol with tourmaline powder, gelation, desiccation, and heat treatment. The MSPSM can be photoexcited by ultraviolet, visible light, and microwave, thus improving its effect of photolysis. It has a rather strong abilities of purifying air, antibacterial, and generating negative air ions.The MSPSM is characterized by means of transmission electron microscope (TEM), scanning electron microscope(SEM), X-ray diffraction(XRD), electron spin resonance(ESR), and ultraviolet visible spectrophotometer(UV-VIS). The results show that: nano-TiO2 doped with rare-earth is an anatase crystal whose grain size is 8~10nm, and nano-TiO2 comparatively evenly distribute on the surface of tourmaline particles, and the tourmaline particles are well separated. The MSPSM in which nano-TiO2 is doped with Ce can produce more OH free radicals than that is doped with La or Nd. And compared with when the Ce/Ti mol ratio is 0.5% and 1.0%, when Ce/Ti mol ratio is 0.8% more OH free radicals are prouced.The MSPSM's abilities of purifying air, antibacterial, and generating negative air ions are studied. Since the material can produce OH free radicals (OH free radicals are oxidant to react with pollutant such as nitrogen oxides, formaldehyde, and bacteria), it can purify air. The MSPSM is also a kind of inorganic antibacterial material with high resistance to high temperature. It can kill bacteria effectively and the rate of sterilization is up to 99%. At the same time, the MSPSM can generate negative air ions at the quantities of more than 700-1000 ions/cm3, and that is good to human health.After mixing with the MSPSM, an inorganic coating, an organic coating, and theair-purifying coating for external wall which is made by Chinese Building Materials Academy all show the abilities of purifying air, antibacterial, and generating negative air ions.The MSPSM has excellent performance, can be widely used in decorative building materials.