超支化聚合物-氯化红血素/TiO2复合光催化剂及其光催化性能

Hyperbranched Polymer-Hemin/TiO2 Composite Photocatalyst and Its Photocatalytic Performance

  • 摘要: 随着环境污染问题的日益严峻,开发高效、环境友好的光催化剂以降解有机污染物成为研究的热点。本研究采用超支化聚缩水甘油(HPG)和氯化血红素(hemin)改性二氧化钛(TiO2),制备了新型可见光响应型光催化剂HPG-hemin/TiO2。通过溶胶凝胶法合成了系列HPG-hemin/TiO2复合材料,系统研究了HPG质量分数对光催化剂性能的影响。X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis DRS)等表征结果表明,HPG的引入未改变TiO2的锐钛矿晶型,且有效增强了材料在可见光区域的光吸收能力。光催化降解实验结果显示,在可见光照射下,HPG-hemin/TiO2对亚甲基蓝(MB)的降解效率高达88.52%,显著优于纯TiO2。进一步的电子顺磁共振波谱(EPR)测试验证了HPG-hemin/TiO2在光催化反应中产生大量羟基自由基(•OH)和超氧阴离子自由基(\text•\textO_2^-)来降解MB,从而提高了光催化性能。本研究为TiO2基光催化剂的改性提供了新思路,对环境污染治理和有机污染物处理具有重要的应用前景。

     

    Abstract: With the increasing severity of environmental pollution issues, the development of efficient and environmentally friendly photocatalysts for the degradation of organic pollutants has become a hot topic of research. This study modified titanium dioxide (TiO2) with hyperbranched polyglycerol (HPG) and hemin to prepare a new type of visible light-responsive photocatalyst, HPG-hemin/TiO2. A series of HPG-hemin/TiO2 composite materials were synthesized via the sol-gel method, and the influence of the mass fraction of HPG on the photocatalytic performance was systematically investigated. Characterization results from X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) indicated that the introduction of HPG did not alter the anatase crystal phase of TiO2 and effectively enhanced the material's light absorption capability in the visible light region. Photocatalytic degradation experimental results showed that under visible light irradiation, the degradation efficiency of HPG-hemin/TiO2 for methylene blue (MB) reached up to 88.52%, significantly superior to that of pure TiO2. Further electron paramagnetic resonance (EPR) testing confirmed that HPG-hemin/TiO2 generated a large amount of hydroxyl radicals (•OH) and superoxide anion radicals (\text•\textO_2^- ) in the photocatalytic reaction to degrade MB, thereby enhancing the photocatalytic performance. This study provides new insights into the modification of TiO2-based photocatalysts and has significant application prospects for environmental pollution control and the treatment of organic pollutants.

     

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