Construction of nano-flower MIL-125(Mo)-In2Se3 Z-scheme heterojunctions by one-step solvothermal method for removal of tetracycline from wastewater in the synergy of adsorption and photocatalysis way

The synergy of adsorption and photocatalysis has received considerable attention in the field of environmental remediation. In this work, a novel nano-flower MIL-125(Mo)-In2Se3 (M-In) adsorbent photocatalyst was firstly prepared by one-step solvothermal method. Benefiting from the 3D nano-flower structure, tightness 2D/2D heterojunction interface, highly exposed active site of MIL-125(Mo) and the spontaneous polarization of lamellar In2Se3, M-In exhibited an excellent adsorption and photodegradation performance in removal of tetracycline (TC) pollutants. The results of adsorption kinetic and adsorption equilibrium were well fitted by Pseudo-second-order model and Freundlich isotherm model, indicating that the adsorption progress was non-uniform and multilayer. In addition, the degradation rate of TC reached 94.14% within 120 min under visible light exposure in the presence of optimum ratio M-In-1. The results of trapping experiments, three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy and liquid chromatograph-mass spectrometer showed that h+ played a significant role and O2– also played a role in the photo-degradation process. Hence, the novel adsorbent photocatalyst can be used to treat TC wastewater and the study gives some inspiration for the design and construction of efficient photocatalysts.