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 (TiO
2) with hyperbranched polyglycerol (HPG) and hemin to prepare a new type of visible light-responsive photocatalyst, HPG-hemin/TiO
2. A series of HPG-hemin/TiO
2 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 TiO
2 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/TiO
2 for methylene blue (MB) reached up to 88.52%, significantly superior to that of pure TiO
2. Further electron paramagnetic resonance (EPR) testing confirmed that HPG-hemin/TiO
2 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.