Valorization of Dental Ceramic Waste with High Silicate Content for the Support of CuO Nanoparticles: Application to the Reduction of Organic Pollutants

The recycling of dental ceramics is currently being explored for healthcare waste management, primarily for robust applications without added functionality. In this study, a solid silicate dental waste is transformed into a multifunctional ceramic material by doping it with varying concentrations of copper nitrate, produced by a solid–solid reaction followed by heat treatment. This waste, composed mainly of a vitreous silicate matrix, is transformed into porous powders doped with different CuO content. X-ray fluorescence analysis establishes a controlled increase in CuO content, while X-ray diffraction, TEM, and SEM/EDX analyses reveal CuO-like phases distributed within an amorphous silicate matrix, maintaining its integrity despite structural changes and its porous nature. The CuO-modified samples were tested by reducing organic pollutants such as 4-NP, methylene blue (MB), and methyl orange (MO) in a simple system in the presence of NaBH4. The catalytic reaction was extremely rapid for all dyes. In terms of efficiency, the high-CuO catalysts performed best, with all dyes exhibiting the highest rate constant. Reusing this catalyst in multiple dye reduction cycles resulted in complete conversion of the organic pollutants in each cycle, demonstrating its stability and performance.