Low-Cost Titania-Hydroxyapatite (TiHAp) nanocomposites were synthesized for removal of Methylene blue under Solar and UV irradiation

Water pollution from industrial dyes like methylene blue (MB) poses significant environmental and health risks due to their toxicity and persistence. In this study, we synthesized a novel titania-hydroxyapatite (TiHAp) nanocomposite via a low-cost, scalable sol-gel method to address these challenges. The composite was comprehensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Photocatalytic degradation of MB under both solar and UV irradiation was evaluated using kinetic (pseudo-first-order and pseudo-second-order) and isotherm (Langmuir and Freundlich) models, demonstrating hydroxyapatite's key role in enhancing adsorption and facilitating effective interactions with the catalyst. Under optimized conditions, the TiHAp nanocomposite achieved 96.58 % degradation of MB at an initial concentration of 120 mg/L and retained over 95 % activity after five reuse cycles. These results illustrate that the synergistic combination of TiO₂'s photocatalytic activity and HAp's adsorptive capacity produces a highly effective composite for degrading organic pollutants. The study underscores the potential of TiHAp nanocomposites as sustainable materials for wastewater treatment applications, while future work will explore their performance against a broader range of contaminants under realistic environmental conditions. • TiHAp nanocomposites remove methylene blue under solar and UV irradiation. • Sol-gel synthesis yields stable, reusable TiO₂-HAp photocatalysts. • Hydroxyapatite enhances dye adsorption and photocatalytic efficiency. • TiHAp achieves 96.58 % MB degradation at 120 mg/L concentration. • Composite retains >95 % activity after five photocatalytic cycles. • BET analysis confirms increased porosity and surface area. • Pseudo-second-order kinetics best fits degradation data. • Scalable, low-cost material for sustainable wastewater treatment.