In Situ Growth of Copper Metal–Organic Frameworks (MOFs) into Ceramics for Catalytic Hydrogenation of Organic Dyes

Abstract

In this study, the in situ solvothermal synthesis of a copper-based metal–organic framework (Cu-BTC MOF) into two porous ceramic substrates with a 10 cm diameter and 2 cm thickness was reported. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, diffuse reflectance spectroscopy (DRS), Tauc plot analysis, optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were the techniques that were utilized to verify the formation and incorporation of the MOF into ceramics (two samples, with different SiO2 particles; 500 µm (Ceramic 1), and 150 µm (Ceramic 2)). The synthesized Cu-MOF exhibited a crystalline structure. Both the composites and the Cu-MOF exhibited visible-light absorption, with optical band gaps of 2.5 eV and 2.4 eV, respectively, as determined by DRS. TEM images demonstrated that crystalline MOF domains were successfully included inside the ceramics. Methyl orange (MO), Congo red (CR), and methylene blue (MB) were used to assess the composites’ ability to remove dyes. Catalytic hydrogenation, powered by in situ hydrogen production from NaBH4 hydrolysis, demonstrated high removal efficiencies of 91–97% after 60 min. Adsorption, on the other hand, was ineffective. Despite undergoing four consecutive cycles without performance degradation, the materials demonstrated remarkable recyclability. Cu-MOF@ceramic composites are effective, durable, and practically applicable for improved wastewater treatment.