Tailoring of PVDF for retrieval of piezoelectric powders to optimize piezo-catalytic water treatment

Powder-based piezoelectric catalysts have been widely examined due to their high catalytic activity for applications such as water treatment and dye degradation. However, challenges remain which are associated with secondary pollution as a result of employing a powder-based catalyst. While the use of bulk catalysts can overcome this challenge, their catalytic activity has been shown to decrease significantly compared to fine-scale catalytic powders. In this study, a simple, efficient, cost-effective and in situ approach is developed that is able to successfully retrieve a powder-based catalyst by coating catalytic particles with dopamine and exploiting the interaction between dopamine and a porous polyvinylidene fluoride (PVDF) substrate to collect the catalytic particles. Detailed characterisation and molecular dynamics modeling are used to determine the mechanisms of the chemical interactions and piezocatalysis. The universality of this new approach is demonstrated by conducting a range of experiments with a range of ceramic particulates, catalyst morphologies and potential dyes. Using this new strategy, we demonstrate the ability of ferroelectric particles to achieve a high piezocatalytic activity while being anchored onto a porous PVDF layer, thereby limiting secondary pollution. This work therefore provides a novel approach for the retrieval of powder-based catalysts, with potential to expand their application potential to other forms of powder-based catalysts.