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. In this study, titanium dioxide (TiO
2) was modified with hyperbranched polyglycerol (HPG) and hemin to prepare a novel 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 pristine TiO
2. Further electron paramagnetic resonance (EPR) spectroscopy confirmed that HPG-hemin/TiO
2 generated a large amount of hydroxyl radicals (•OH) and superoxide anion radicals (\text•\textO_2^- ) during the photocatalytic reaction to degrade MB, thereby enhancing the photocatalytic performance. This study provides new insights into the modification of TiO
2-based photocatalysts and has significant application prospects in environmental pollution control and the treatment of organic pollutants.