原位合成H_4SiW_(12)O_(40)@C协同UV/H_2O_2降解罗丹明B模拟废水

Synergetic degradation of Rhodamine B in simulated wastewater using ultraviolet and hydrogen peroxide catalyzed by H_4SiW_(12)O_(40)@C synthesized in situ

以H4Si W12O40及可溶性淀粉为起始原料,原位合成了H4Si W12O40@C光催化剂,并采用SEM、EDS、XRD、FTIR、UV-vis、BET对其进行了表征。对H4Si W12O40@C协同UV/H2O2降解罗丹明B废水工艺进行了研究,考察了不同因素对降解效果的影响及协同效应,并探讨了催化氧化反应机理。研究结果表明:UV-Si W20@C-H2O2体系能高效快速降解废水中的罗丹明B,产生了明显的协同效应。在优化工艺条件下,即在250m L初始p H值为3、质量浓度为100mg/L的罗丹明B废水中,Si W20@C催化剂0.15g、H2O2浓度14mmol/L、温度25℃、高压汞灯功率500W、紫外照射70min条件下,罗丹明B脱色率达到了95.78%。紫外可见光谱和HPLC结果显示,罗丹明B分子结构被破坏,分解成了含苯环结构等有机小分子。此外,Si W20@C催化剂还具有较好的重复使用性能。

The H4SiW12O40@C photocatalysts synthesized in situ from silicadodecatungstic acid（SiW12）and soluble starch were studied and characterized by SEM,EDX,XRD,FTIR,UV-vis and BET in this research. The degradation of Rhodamine B（Rh B） wastewater with H4SiW12O40@C photocatalysts and hydrogen peroxide was investigated under ultraviolet irradiation. The effects of different factors and synergetic effects on the degradation of Rh B were investigated and the mechanism of catalytic oxidation of Rh B was discussed. The results showed that the Rh B was degraded efficiently. The decoloration efficiency of the Rh B was up to 95.78% with the initial p H value of 3 and Rh B concentration of 100mg/L under optimal reaction conditions（i.e. SiW20@C of 0.15 g,dose of hydrogen peroxide concentration of 14mmol/L,reaction temperature of 25℃,the high pressure mercury lamp power of 500 W,the radiation time of 70min）. Degradation process of Rh B wastewater by ultraviolet,hydrogen peroxide and SiW20@C had synergetic effects. UV-vis spectroscopy and HPLC results of the wastewater showed that the conjugating structure of Rh B was destroyed,phenylcontained and small molecular compounds were included in the solution. In addition, the SiW20@C photocatalyst also showed good reusability.