Fabrication and Optimization of 3D-Printed TiO2/g-C3N4 Scaffolds for Degradation of Organic Dye and Pharmaceutical Pollutant

The contamination of synthetic dyes in aquatic environments remains a major challenge because of their toxic nature and poor degradability under conventional treatment processes. Additionally, pharmaceutical residues such as paracetamol have emerged as persistent contaminants owing to their extensive consumption and continuous release into water systems, posing potential ecological and health risks. In this research work, we developed 3D-printed scaffolds embedded with TiO2/g-C3N4 composites to degrade methylene blue (MB) and paracetamol from aqueous solutions. TiO2 was synthesized via a hydrothermal method, while g-C3N4 was prepared through thermal polymerization. The various ratios of TiO2/g-C3N4 composites with varying mass ratios were fabricated to evaluate the effect of compositional variation on photocatalytic efficiency. The optimized composites were incorporated into photocurable resin and shaped into porous scaffolds using stereolithography (SLA). Structural and surface characterizations verified the successful development of uniformly dispersed TiO2-g-C3N4 heterostructures throughout the printed matrices. Adsorption tests in dark conditions for 30 min ensured equilibrium before light irradiation. Photocatalytic activity was assessed under UVA irradiation (λ = 365 nm) and demonstrated efficient degradation of both MB and paracetamol, with the optimized TCN (10:3) scaffold achieving removal efficiencies of 95% and 83%, respectively, within 210 min. Furthermore, reusability experiments revealed that the optimized scaffolds retained stable performance over five repeated uses. This work highlights the potential of combining heterojunction photocatalysts with 3D printing to develop reusable materials for the efficient removal of both dye and pharmaceutical contaminants from wastewater.