Efficient immobilization of TiO2 on silk screens for enhanced photocatalytic wastewater treatment

Abstract

BACKGROUND

Advanced oxidative processes (AOPs) have emerged as a promising alternative for wastewater treatment, with photocatalysis standing out as a particularly effective approach. The use of titanium dioxide (TiO₂) as the primary photocatalyst is well-established among researchers, especially in suspension. However, the challenge of separating the catalyst powder from the treated effluent has driven the development of immobilized catalyst systems. Immobilization facilitates catalyst reuse, provided that an adhesion method ensures strong attachment to the support material, preventing catalyst loss during repeated cycles.

RESULTS AND CONCLUSION

The study investigated the immobilization of TiO₂ on screens for photocatalytic processes, aiming for improved reuse and pollutant degradation efficiency. The wash-coating method was used to test different supports and drying conditions. The best result was obtained with P25 TiO₂ immobilized on a silk screen and dried at 80 °C for 36 h, ensuring a uniform and adherent coating. Characterization by SEM, EDX, FTIR, and ATR confirmed the catalyst's presence, and the band-gap value was consistent with the literature. The material achieved over 95% methyl orange degradation, with optimal performance at pH 4. Reuse tests showed high stability, maintaining efficiency after five cycles. Comparison with photolysis confirmed that photocatalysis was the primary degradation mechanism. The results highlight the effectiveness of immobilized TiO₂ on silk screens as a low-cost and sustainable alternative for wastewater treatment. © 2025 Society of Chemical Industry (SCI).