氟铌酸钾的低温固相法合成及其对甲基橙的光催化降解性能

以草酸铌、草酸钾和氟化钾为原料,采用改进的固相法在较低温度(600℃)下合成了层状K2NbO3F;测定了其对甲基橙光催化降解的催化作用,并基于紫外-可见漫反射光谱分析和X射线衍射分析初步探讨了甲基橙在自然光照条件下的光催化反应过程及降解机理.结果表明,合成的K2NbO3F与微量H2O2作用后,在自然光照条件下几乎可以使甲基橙染料完全降解;当反应温度为45℃,催化剂投加量为1g/L,H2O2用量为0.33%(体积分数)时,2h内可将初始浓度为15mg/L的甲基橙溶液几乎完全降解.就甲基橙的光催化降解机理而言,·OH自由基在其降解过程中起重要作用.

Synthesis of potassium fluoneobate by low temperature solidstate method and its photocatalytic performance for degradation of methyl orange

Niobium oxalate, potassium oxalate and potassium fluoride were used as raw materials to synthesize layered compound K2 NbO3 F by a modified solid-state method at a lowered temperature of 600 ℃. The catalytic performance of as-synthesized product for the photocatalytic degradation of methyl orange （denoted as MO） was evaluated. The photocatalytic reaction process and degradation mechanism of MO under natural light irradiation were preliminarily explored based on analyses of ultraviolet-visible light diffuse reflectance spectrometry and X-ray diffraction. It was found that as-synthesized K2 NbOa F mixed with trace amount of H2 O2 is able to almost completely degrade MO under natural light irradiation. Namely, the MO solution with an initial concentration of 15 mg/L can be nearly completely degraded within 2 h at 45 ℃ in the presence of 1 g/L K2NbO3F catalyst and 0.33G （volume fraction） H2O2. Moreover, in terms of the photocatalytic degradation mechanism of MO, . OH free radical plays an important role.