Comparative photocatalytic performance of TiO2 and TiO2/en-MIL-101 (Cr) for degradation of rhodamine B as a model of pollutant under UV and visible irradiations

In this research, a new photocatalyst of TiO2/en-MIL-101 (Cr) was synthesized via hydrothermal method. The as-prepared hetrostructure material was characterized by X-ray diffraction, Fourier Transform Infrared Spectrometer, energy dispersive X-ray spectroscopy, ultraviolet-visible diffuse reflection spectra, scanning and transmission electron microscopy. The photodegradation of rhodamine B by the synthesized photocatalysts was investigated under UV irradiation and visible light. The results showed that immobilization of TiO2 on the surface and inside the photocatalytic structure enhanced the degradation of the pollutant. The band gap energy of the synthesized TiO2/en-MIL-101(Cr) measured by ultraviolet-visible diffuse reflection spectra showed that an insignificant shift to lower energy was situated after immobilization onto the structure of the supports. The relationship between the photocatalytic activity and the structure of TiO2/en-MIL-101(Cr) hetrostructure was discussed. The degradation efficiency of 84% and 77% of rhodamine B was respectively obtained by TiO2/en-MIL-101(Cr) under Uv and visible light, respectively. This work has introduced a new way for using the MOF in the design of photocatalyst substrate for organic dyes degradation in waste water.