Bioinspired Synthesis of Photocatalytic Nanocomposite Membranes Based on Synergy of Au-TiO₂ and Polydopamine for Degradation of Tetracycline under Visible Light

Abstract

A bioinspired photocatalytic nanocomposite membrane was successfully prepared via polydopamine (pDA)-coated poly(vinylidene fluoride) (PVDF) membrane, as a secondary platform for vacuum-filtrated Au-TiO nanocomposites, with enhanced photocatalytic activity. The degradation efficiency of Au-TiO/pDA/PVDF membranes reached 92% when exposed to visible light for 120 min, and the degradation efficiency of Au-TiO/pDA/PVDF membranes increased by 26% compared to that of Au-TiO powder and increased by 51% compared to that of TiO/pDA/PVDF nanocomposite membranes. The degradation efficiency remained about 90% after five cycle experiments, and the Au-TiO/pDA/PVDF nanocomposite membranes showed good stability, regeneration performance, and easy recycling. The pDA coating not only served as a bioadhesion interface to improve the bonding force between the catalyst and the membrane substrate but also acted as a photosensitizer to broaden the wavelength response range of TiO, and the structure of Au-TiO/pDA/PVDF also improves the transfer rate of photogenerated electrons; the surface plasmon resonance effect of Au also played a positive role in improving the activity of the catalyst. Therefore, we believe that this study opens up a new strategy in preparing the bioinspired photocatalytic nanocomposite membrane for potential wastewater purification, catalysis, and as a membrane separation field.

Effect of Mussel‐Inspired Poly(Dopamine)‐Functionalized Carbon Nanotubes/Graphene Nanohybrids on Interfacial Adhesion of Soy Protein‐Based Nanocomposites

“…Such visual feature indicated the strong interfacial interactions between the SPI and graphene/PDCNTs hybrids . This result was possible due to the favorable multiple interface adhesion between the two phases due to the covalent linkage of PDA . In addition, the three‐phase structure of SPI/G/PDCNTs hybrids could cause effective stress transfer from the SPI substrate to the graphene and PDCNTs reinforcing nanofillers, thereby reducing the stress concentration and improving the mechanical properties of the nanocomposite film .…”

Preparation and Performance of Visible‐Light‐Driven Bi2O3/ZnS Heterojunction Functionalized Porous CA Membranes for Effective Degradation of Rhodamine B

“…This is the key to reduce the recombination rate of the electron–hole pairs. The active species ( • O 2 − ) and the photoinduced holes reacted directly with RhB to yield degradation products . However, the CA membranes played a substrate support and absorption role with no photocatalytic activity.…”

“…The active species ( • O 2 À ) and the photoinduced holes reacted directly with RhB to yield degradation products. [30] However, the CA membranes played a substrate support and absorption role with no photocatalytic activity. In summary, this Bi 2 O 3 / ZnS heterojunction structure can effectively separate electron-hole pairs, which made more • O 2 À and holes to participate in oxidation reactions and improve the photocatalytic activity.…”

“…The most common method for fabricating the photocatalytic membranes is to blend the catalyst into a membrane matrix. The common membrane matrix includes polyvinylidenefluoride (PVDF), polysulfone (PSf), cellulose acetate (CA), etc. Among these, CA‐based membranes have been widely utilized as support membranes due to the advantages of biodegradability, nontoxicity and low cost .…”

Bio‐Inspired Plasmonic Photocatalysts

“…This strategy can be expanded to Au‐TiO 2 photocatalyst system also. Huo and co‐workers synthesized a catalytic nanocomposite membrane, introducing Au‐TiO 2 onto poly(vinylidene fluoride) (PVDF) membrane for degrading of tetracycline …”