An attachable, self-healing and durable TiO2/rGO/PVA photocatalytic hydrogel band for dye degradation†

This work presents the fabrication of a photocatalytic hydrogel band through facile one-pot processes of mixing with TiO₂ nanotubes (TiNT)/graphene oxide sheets (GO)/polyvinyl alcohol (PVA), in situ photoreduction of GO and freeze–thaw gelation. The interactions between TiNT/rGO/PVA make the constructed porous gel network possess good mechanical strength with flexibility and self-healing capability. The gelation matrix also allows the TiNT/rGO/PVA hydrogel band to easily adhere to various smooth surfaces. The structural and optical analysis of the TiNT/rGO/PVA hydrogel bands indicated that the binding of rGO on TiNT can boost the photocatalytic activity by accelerating charge separation and inhibiting charge recombination of TiO₂. Due to the combined effects of enhanced activity, porous features to facilitate molecular diffusion, and improved mechanical strength, the TiNT/rGO/PVA hydrogel bands exhibited excellent photocatalytic performance for the decomposition of dyes with well-maintained activity without a loss after repeated usages. These results showed the potential of hydrogel-based photocatalytic systems for more convenient and reliable usages in environmental remediation.