Research On Hydrothermal Synthesized TiO₂ Thin Films And Its Removal To Humic Acid In Water

In this research, spring-loaded glass nano-TiO2 thin films was synthesized by hydrothermal method with titanium sulfate as precursor and urea as precipitation agent. It was seriously combined with the glass surface, and its grain size was uniform which size in about 20 ~ 30nm were antase. UV - visible spectrophotometer scanning analysis showed that the ultraviolet of wavelengths less than 350nm was strongly absorbed by nano-TiO2 photocatalyst; The physical and chemical properties of thin films was relatively stable, and its fluid erosion rate was small. When the concentration of titanium sulfate being 0.5mol / L, the concentration of urea being, 1.0mol / L, the hydrothermal reaction temperature being 200℃and reaction for 2 hours, the catalyst prepared could most effectively degrade the humic acid solution of 8mg/L.And and humic acid concentration and reaction time showed significant linear correlation, eing zero-order reaction.Secondly, the products performed a high photocatalytic activity during that humic acid in water was photocatalytically degraded in the home-made devices, The results showed that when the initial humic acid concentration of 8mg / L, pH value of 6.1, ultraviolet light intensity for 34μW ? m-2 (25W), air flux at 2L/min, reaction temperature control about 20℃, when, the removal rate of HA was the highest. It was up to 85% in four hours'reaction, and 90.6% was achieved in eight hours. Compared to only TiO2 catalyst, the removal rate of humic acid was significantly increased in the UV/TiO2/O2 and UV/O2 complex systems, which confirmed that the UV and TiO2 photocatalysis had obvious synergies in HA degradation.Lastly, spring-loaded Zn2 + / TiO2 complex catalyst prepared by hydrothermal method was tightly combined with the glass surface. When the amount of Zn2 +-doped was 0.6%, the particles of catalyst surface were significantly refined with an average particle size in about 20 ~ 50nm and the apparent cavities distributed among the particles; Their phase composition was mainly anatase, while a weak characteristic peaks of rutile phase.Zn2 +-doped could improve photocatalytic degradation ability of the catalyst TiO2. The best amount doped (molar ratio) was 0.6%, the degradation rate of humic acid was achieved 90.1% in 4h reaction. While the absorption spectra of TiO2 red shift occurred to improve its utilization of sunlight; Ozone access could significantly increase the efficiency of the degradation of HA, and increasing with the increased access, which reached 90.3% in 4h. This result confirmed that the use of sun-ray to HA degradation had a high practical value.