纳米TiO_(2)光催化混凝土的制备及性能研究

Preparation and properties of Nano-TiO_(2) photocatalytic concrete

利用行星球磨技术制得Fe^(3+)掺杂改性纳米TiO_(2),分别将纳米TiO_(2)和改性纳米TiO_(2)掺入混凝土中制备光催化混凝土试件,测试其力学强度、抗冻性能和光催化性能,并从微观角度分析改性纳米TiO_(2)光催化混凝土的作用机理。结果表明:纳米TiO_(2)混凝土和改性纳米TiO_(2)混凝土力学强度均高于基准混凝土;随着纳米TiO_(2)掺量的增加,2种光催化混凝土的质量变化率均呈先减小后增大的趋势;改性纳米TiO_(2)混凝土的光催化降解速率比纳米TiO_(2)快11%~20%;微观形貌和能谱分析显示,改性纳米TiO_(2)可以有效填充水化产物的裂缝和孔隙,优化界面过渡区结构,提高混凝土的密实性和光催化能力。综合考虑各项性能和经济性,推荐改性纳米TiO_(2)的最佳掺量为5%。

Fe^(3+) doped mano-TiO_(2) was prepared by planetany ball milling techaology.Nano-TiO_(2) and modified TiO_(2) were added into concrete to prepare photocatalytic concrete specimens,the mechanical strength,frost resistance and photocatalytic properties of the specimens were tested.The mechanism of the modified nano-TiO_(2) photocatalytic concrete was analyzed from the microscopic point of view.The results show that the mechanical strength of the original and modified nano-TiO_(2) concrete are higher than those of benchmark concrete.With the increase of the content of nano-TiO_(2) material,the mass change rate of two photocatalytic concretes showed a trend of first decreasing and then increasing.The photocatalytic degradation rate of modified nano-TiO_(2) concrete is about 11%~20%faster than that of original nano-TiO_(2).The microscopic morphology and energy spectrum analysis show that the modified nano-TiO_(2) can not only effectively fill the cracks or pores of hydration products,but also optimize the structure of the interface transition zone.As a result,the compactness and photocatalytic ability of concrete are improved.Considering various performance and economy,it is recommended that the optimal content of modified nano-TiO_(2) is 5%.