Egg-white Templating of Hierarchically Macroporous Architectures of SiO2, TiO2 and C/SiCN Nanocables, and Photocatalytic Properties

Egg-white was found to exist in the form of ladder-like structure after a freeze-drying process. Several hierarchically ordered macroporous structures were synthesized by sol-gel method with egg-white template, such as the 3D ladder-like structures of SiO2, TiO2, and C/SiCN nanocables. Thermogravimetric (TG), differential scanning calorimetry (DSC), Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high-resolution TEM (HRTEM) were employed to characterize the novel macroporous architecture. The results indicate that the hierarchically macroporous architectures were copied completely. The photocatalytic properties of TiO2 replica were also studied. The nearly linear relationship of the MO degradation percentage vs irradiation time suggests that the reaction follows a first-order kinetic mode. Within 2 h, the degradation rate of the methyl orange was reached at 99%, indicating a high efficient photocatalytic property of this ordered TiO2 macroporous architecture.