Membranes modified with photocatalytic structures based on TiO₂ nanoparticles and carbon nanoparticles

Title : Membranes modified with photocatalytic structures based on TiO₂ nanoparticles and carbon nanoparticles

Abstract:

The membranes (MEMs), modified through the incorporation of photocatalytic structures as for example the one based on TiO2 nanoparticles in combination with different types of carbon nanoparticles, represent a valuable alternative to conventional systems used for physical  filtration. They are acting as hybrid structures which benefit not only of their overall properties generated by their components but also of their synergic action. The PVC membrane plays double role both in physical separation processes and as a catalyst support offering an extended contact at the interface with the contaminated water flux through the uniform distribution of the catalyst nanoparticles.

In this study, we used MEMs that were prepared using the phase inversion method and modified with photocatalytic blends based on TiO₂ nanoparticles and carbon nanostructures (CNs). The aim was to remove dyes from water. The main CNs used were reduced graphene oxide (RGO), single-walled carbon nanohorns (SWCNH), and single-walled carbon nanotubes (SWNTs).

The focus will be on the characterization and testing of the MEMs based on PVC, TiO₂ and different type of CNs, in dye photodegradation reaction.  Both Raman scattering and FTIR spectroscopy will be used to characterise the membranes, highlighting the contribution of the TiO₂/CNs to the performance of the PVC/TiO₂/CNs MEMs. The results obtained show that the dye degradation efficiency increased when using PVC/TiO₂/CNs MEMs compared to using PVC/TiO₂ MEMs.

In the investigated MEMs, CNs act as receptors for the photoinduced electrons generated in TiO₂. This reduces the recombination of electron–hole pairs, which normally limits the photocatalytic activity of TiO₂. Consequently, more electrons and holes are available to form reactive species such as hydroxyl and superoxide radicals, accelerating the degradation of dyes.

Of all the carbon nanoparticle tested within the PVC/TiO₂ MEMs, the PVC/TiO₂/SWNT MEMs proved to be the most efficient at photo-degrading dyes. This is due to the more efficient transfer and separation of electrical charges between the TiO₂ and the SWNTs, leading to an improved UV absorption and a longer lifetime of charge carriers.

Biography:

Dr. Mirela Vaduva (formerly Ilie) is a researcher specializing in advanced materials science, with a focus on composite materials and their applications. She is affiliated with research projects in the field of water management and innovative material technologies, contributing as a postdoctoral researcher within multidisciplinary scientific teams. Her work is connected to the development and characterization of composite materials for practical engineering applications. Through her ORCID profile, she is identified as an active contributor to collaborative research initiatives, demonstrating involvement in both experimental and applied studies. Her academic activity reflects a strong engagement in materials research and interdisciplinary scientific projects.