An improvement of water supply and sanitation and better management of water resources, especially in terms of water reuse, is one of the priorities of the European Green Deal. In this context, it is crucial to find new strategies to recycle wastewater efficiently in a low-cost and eco-friendly manner. The immobilization of inorganic nanomaterials on polymeric matrices has been drawing a lot of attention in recent years due to the extraordinary properties characterizing the as-obtained nanocomposites. The hybrid materials, indeed, combine the properties of the polymers, such as flexibility, low cost, mechanical stability, high durability, and ease of availability, with the properties of the inorganic counterpart. In particular, if the inorganic fillers are nanostructured photocatalysts, the materials will be able to utilize the energy delivered by light to catalyze chemical reactions for efficient wastewater treatment. Additionally, with the anchoring of the nanomaterials to the polymers, the dispersion of the nanomaterials in the environment is prevented, thus overcoming one of the main limits that impede the application of nanostructured photocatalysts on a large scale. In this work, we will present nanocomposites made of polymers, i.e., polymethyl methacrylate (PMMA), and photocatalytic semiconductors, i.e., TiO₂ nanoparticles (Evonik). MoS₂ nanoflakes were also added as co-catalysts to improve the photocatalytic performance of the TiO₂. The hybrid materials were prepared using the sonication and solution casting method. The nanocomposites were deeply characterized, and their remarkable photocatalytic abilities were evaluated by the degradation of two common water pollutants: methyl orange and diclofenac. The relevance of the obtained results will be discussed, opening the route for the application of these materials in photocatalysis and especially for novel wastewater remediation.

Silicon carbide porous flakes are obtained during electrochemical etching (ECE) of n-doped 4H-SiC wafers. In particular, the use of high current conditions (50–500 mA cm⁻²) causes detachment of silicon carbide residues from the surface of the etched wafers. Herein, comprehensive material characterization demonstrates the possibility of collecting and using these secondary products of the SiC ECE process. In particular, etching of the two different 4H-SiC faces (Si-face and C-face) results in producing porous flakes, characterized by different structural and chemical properties as investigated using N₂ adsorption isotherms, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). Adsorption properties in a water environment were investigated using different classes of dyes (cationic, anionic, and neutral) such as methylene blue, methyl orange, rhodamine B, rhodamine 6G, and thiazolyl blue tetrazolium. The preferential adsorption of the positively charged species well confirms the negative surface charge of the flakes, even though other factors such as steric hindrance and charge screening influence the dye–flake interaction. Methylene Blue (MB) is the most efficiently adsorbed dye and is used as a model to study the adsorption mechanism on both Si and C-face flakes by a thermodynamics and kinetics investigation. The Langmuir model best describes the adsorption mechanism of MB by Si-face generated flakes whilst both Langmuir and Freundlich models fit well the C-face flake adsorption behavior and the kinetic study indicates that the diffusion stage of adsorption is faster than the dye–dye stacking. This preliminary study of the properties of SiC flakes demonstrates their applicability in environmental applications as adsorbent materials whose activity can be mastered by coupling the SiC photocatalytic properties. Moreover, their intrinsic porosity makes possible the dimensional scaling down of these SiC flakes by mechanical sonication to produce SiC nanoparticles as alternative approaches to high-energy ball milling, carbothermic reduction, or laser ablation.

Unlock face-dependent photocatalytic performance in porous 4H-SiC flakes fabricated by electrochemical etching establishing SiC as a next-generation platform for clean-energy and environmental remediation.