Efficient and reusable 3D TiO2@PDMS sponge composites for solar driven photocatalytic degradation of water pollutants

The rapid growth of the global population has increased the need for efficient fabrication methods and materials to purify polluted water. In this study, we report the fabrication and characterization of reusable and efficient three-dimensional (3D) polydimethylsiloxane (PDMS) sponge composites designed for water treatment applications. By varying the ratios (10/90, 30/70, and 50/50) of large and small sacrificial templates’ particles used in the fabrication method, we tailored the sponge’s morphology and the interconnected pores’ distribution. To achieve an enhanced photocatalytic activity, we incorporated titanium dioxide (TiO2) at different concentrations (1 % TiO2, 5 % TiO2, and 10 % TiO2 w/w) into the PDMS matrix. Scanning electron microscopy (SEM) was used to evaluate the structure of both 3D PDMS and TiO2@PDMS sponges, while energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) confirmed the successful incorporation of TiO2 into the sponge framework. The photocatalytic performance of the 3D TiO2@PDMS composites was assessed by monitoring the degradation of Rhodamine B (RhB) under solar light irradiation, and the results were compared to those obtained using reference (TiO2-free) sponges under identical conditions. Very low Ti leaching effect have been evidenced by using Inductively Coupled Plasma−Mass Spectrometry (ICP-MS). The reusability of the sponges was demonstrated through complete bleaching of the 554 nm RhB absorption band after four consecutive degradation cycles.