TiO2光催化降解亚硝酸钠的研究

采用溶胶-凝胶法制备了TiO2光催化剂,以紫外光照射下的光催化降解亚硝酸钠为模型反应,以盐酸萘乙二胺显色法测定样品的吸光度,进而得出亚硝酸钠的转化率,并采用BET、XRD和IR对催化剂进行了表征。结果表明,500℃焙烧的TiO2催化剂比表面积为42.5 m2/g,平均孔径为5.8 nm,热稳定性好。400℃焙烧2 h的TiO2尚存在一定量的无定形相TiO2,500℃焙烧的TiO2完全转变为锐钛矿型TiO2,700℃时完全转化为金红石相。本实验最佳的反应条件为:TiO2(500℃,2 h)催化剂0.2 g,100 mL 0.125μg/mL亚硝酸钠溶液中,紫外光降解150 min,亚硝酸钠的降解率为100%;添加适量浓度的H2O2溶液,可促进亚硝酸钠溶液的转化。

Preparation and photocatalytic activity of TiO2 for sodium nitrite

The TiO2 catalysts were prepared by sol-gel method,using photocatalytic degradation of sodium nitrite as a model reaction,its photoactivity was tested by N-(1-naphthyl) ethylenediamine dihydro-chloride chromogenic method,and structure was characterized by BET,TG-DTA,XRD and IR techniques.It suggested that the BET area of TiO2 was 42.5 m2/g,and average pore size was 5.8 nm,and TiO2 had the best thermal stability.Its crystalline was anatase,but rutile at 700 ℃.The photocatalytic activity of TiO2(0.2 g) calcined at 500 ℃ for 2 h for sodium nitrite(100 mL 0.125 μg/mL)degradation showed the best activity,which conversion rate was 100% after 150 min,adding suitable concentration of H2O2 solution,which can promote the conversion of sodium nitrite solution.