A novel polydopamine-coated bacterial cellulose/g-C3N4 membrane for highly efficient photocatalytic degradation of methylene blue

Photocatalytic oxidation emerges as an eco-friendly approach for chemically degrading water-borne organic pollutants. Establishing a more sustainable process for synthesizing photocatalyst membranes with higher efficiency and reusability is crucial for advancing safe water remediation solutions. In this study, we present a novel photocatalytic membrane incorporating bacterial cellulose (BC), a naturally occurring biopolymer with an intricate fibrous network, and graphitic carbon nitride (g-C3N4), a visible light-responsive non-metal photocatalyst. The composite membrane is augmented with a coating of polydopamine (PDA), an amorphous polymeric layer derived from dopamine to enhance light absorption and reduce photoexcited charge recombination. The BC/g-C3N4/PDA membrane demonstrates a substantial improvement in methylene blue removal efficiency, up to 95.39 % within 150 min of irradiation. Moreover, the PDA-modified membrane exhibits noteworthy recyclability, retaining significant photodegradation ability for up to three cycles. This method offers an accessible and scalable approach to fabricating a highly effective photocatalyst composite membrane suitable for industrial applications.