Sustainable TiO₂/sludge ceramic waste nanocomposite for high-efficiency Photodegradation of rhodamine B

Photocatalytic degradation of organic dyes presents a sustainable pathway for wastewater remediation; however, the high cost of conventional catalysts like TiO₂ limits their scalability. This study introduces a cost-effective and eco-friendly approach using industrial sludge ceramic waste (SCW), a hazardous byproduct rich in oxides like SiO₂, Al₂O₃, and CaO, as a useful co-catalyst with TiO₂ nanoparticles. The TiO₂/20wt%SCW composite shown remarkable photodegradation efficiency of 98.6 % for Rhodamine B under UV irradiation, comparable to pure TiO₂ (99.55 %) but at 20 % lower material cost. Structural and surface analysis revealed that SCW incorporation preserved the anatase phase, induced crystallographic strain (XRD), and introduced Ti4+/ 3+ and Ca 2+ surface species (XPS), both of which promoted charge separation. The engineered composite also exhibited a reduced bandgap of 2.96 eV (from 3.2 eV for pristine TiO₂), and a BET surface area of 133.27 m 2 /g, facilitating enhanced light absorption and dye adsorption. This work demonstrates a novel dual valorization strategy—remediating dye pollutants while repurposing ceramic waste—and offers a viable model for designing low-cost, high-performance photocatalysts through waste-derived bandgap and surface engineering. • Sludge ceramic waste reused as co-catalyst with TiO₂ for efficient dye degradation. • TiO₂/20 % SCW degraded 98.6 % of Rhodamine B under UV light. • Bandgap reduction from 3.2 to 2.96 eV by SCW incorporation. • Performance enhancement due to inducing mechanical strain and modified electronic configuration.