2D montmorillonite-supported Ga-doped In-MOF composite for high-efficiency photocatalytic degradation of tetracycline

Abstract

To address the challenge of antibiotic residue remediation, this study employed a hydrothermal method to in-situ construct a bimetallic indium/gallium-based MIL-68 heterostructure on the surface of two-dimensional montmorillonite (MMT). By integrating metal node electronic structure regulation with interface engineering strategies, it provides a feasible approach to improve the low charge carrier separation efficiency in metal-organic framework (MOFs) materials. Experimental results demonstrate that when the MMT loading is 20%, the composite material exhibits obvious enhanced photocatalytic performance for the degradation of 40 mg/L tetracycline solution, with a degradation rate of up to 97% within 60 min using 10 mg of catalyst. This improvement is attributed to the synergistic effect of In/Ga bimetals and the interface charge transfer channels of the MMT 2D matrix, which together induce a Z-type charge carrier migration mechanism, enhancing the separation efficiency of photo-induced electron-hole pairs. After four cycles, the MIL-68(In/Ga)/MMT composite showed good cycling stability and demonstrated broad-spectrum degradation capability, achieving degradation rates of 99% and 79% for rhodamine B and methyl orange, respectively. This composite material shows good photocatalytic performance in dye degradation, providing new research insights for the field of photocatalytic degradation of pollutants.