Attachable, Self-Healing and Durable TiO2/rGO/PVA Photocatalytic Hydrogel Band for Dye Degradation

Abstract

Hydrogel-supported photocatalysts are one of the promising photocatalysis systems for solving the application issues of easy aggregation and poor recycling from nano photocatalysts. However, most photocatalyst-hydrogel composites exist in the form of bulk blocks, which lack flexibility and hinder fast molecular diffusion and incident light penetration. In this work, we successfully fabricated a photocatalysis hydrogel band with the advantages of bendable, attachable, self-healing, durable, and high photocatalytic activity based on a facile one-pot synthesis strategy using TiO2 nanotubes (TiNT), reduced graphene oxide sheets (rGO) and transparent biocompatible polyvinyl alcohol (PVA). The addition of rGO to the hydrogel not only reinforced the linkages between the three components but also boosted the photocatalytic activity by improving adsorption capacity and promoting photo-induced electron transfer from TiO2. The proper incorporation state of TiNT, rGO and PVA is also important to construct the three dimensional gel network with high strength and photoactivity. Combined with moderate swelling capability, the photocatalysis hydrogel band exhibited excellent photocatalytic performance for the decomposition of dyes and well maintained the activity without a loss for repeated usages. These results showed the potential of hydrogel-based photocatalyst systems for more convenient and reliable usages in environmental remediation.