Efficient Removal of High-Concentration Dye Pollutants in Wastewater Using Composite Photocatalyst NH2-MIL-125 (Ti)/g-C3N4 Nanosheets Under Visible Light


 The NH2-MIL-125(Ti)/g-C3N4 nanosheets composite photocatalyst was prepared by one-step solvothermal synthesis and used for the removal of high concentration dye wastewater. The morphology, structure and photoelectrochemical properties of the as-synthesized samples were characterized by XRD, SEM, XPS, FT-IR, UV-vis DRS PL, EIS and transient photocurrent. The results showed that g-C3N4 nanosheets were tightly loaded on the surface of NH2-MIL-125(Ti) to form the NH2-MIL-125(Ti)/g-C3N4 nanosheets composite photocatalyst. Among them, NM (Ti)/CNNS30 showed the best adsorption performance and photocatalytic degradation activity for the removal of high concentration RhB solution. In addition, the optimal experimental conditions such as the concentration of RhB solution, the dosage of NM (Ti)/CNNS30 and the initial pH of RhB were also explored. Finally, the mechanism of photocatalytic degradation of NM(Ti)/CNNS30 on high concentration RhB solution was also proposed based on active species capture experiment and energy band structure analysis. It was inferred that ·O2- and h+ were the main active species for NM(Ti) photocatalytic degradation of high concentration RhB. This work provided new insights into the design and synthesis of highly efficient photocatalysts for the practical treatment of high concentration dye wastewater.