Metal-organic framework templated synthesis of TiO2@MIL-101 core-shell architectures for high-efficiency adsorption and photocatalysis

We report a simple method for preparation of MIL-101 templated TiO2@MIL-101 core-shell architecture, and endeavor to investigate the synergism of TiO2@MIL-101 core-shell composite for the high efficiency adsorption and decomposition of methyl orange (MO). XRD patterns, SEM and TEM images confirmed the core-shell architecture of TiO2@MIL-101 composite. Ti/Cr element ratio of the TiO2@MIL-101 composite from EDAX analysis was 14.8 wt%, which was similar to the calculated 15.8 wt% value. The fabricated composite possessed mesopores with total-pore-volume of 0.475 cm3 g−1 and BET surface area of 1033 m2 g−1. MIL-101 templated TiO2@MIL-101 core-shell composite possessed excellent ability for the adsorption of MO, with the maximum adsorption capacity of 19.23 mg g−1 based on theoretical calculation. Furthermore, higher MO removal efficiency was achieved compared to MIL-101 and TiO2 when TiO2@MIL-101 core-shell composite was used as adsorbent and catalyst, which only took 30 min to reach removal efficiency of 99% under UV irradiation.